I disabled IPv6 but the issue is still there. nmcli con show ... shows:
ipv6.method: ignore
I left everything over night, the next morning (as the day before when I left) I had connection. But after a reboot I lost the connection. Here is the log with the reboot indicated (-- Reboot --):
Feb 24 15:05:13 ************.*****.** dhclient[1264]: receive_packet failed on eno1: Network is down
Feb 24 15:05:19 ************.*****.** NetworkManager[727]: <info> [1614175519.8028] device (eno1): state change: activated -> unavailable (reason 'carrier-changed', sys-iface-state: 'managed')
Feb 24 15:05:19 ************.*****.** NetworkManager[727]: <info> [1614175519.8188] dhcp4 (eno1): canceled DHCP transaction, DHCP client pid 1264
Feb 24 15:05:19 ************.*****.** NetworkManager[727]: <info> [1614175519.8189] dhcp4 (eno1): state changed bound -> done
Feb 24 15:05:19 ************.*****.** NetworkManager[727]: <info> [1614175519.8203] manager: NetworkManager state is now CONNECTED_LOCAL
Feb 24 15:05:19 ************.*****.** NetworkManager[727]: <info> [1614175519.8206] manager: NetworkManager state is now DISCONNECTED
Feb 24 15:05:29 ************.*****.** NetworkManager[727]: <info> [1614175529.9968] device (eno1): carrier: link connected
Feb 24 15:05:29 ************.*****.** NetworkManager[727]: <info> [1614175529.9972] device (eno1): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
Feb 24 15:05:29 ************.*****.** NetworkManager[727]: <info> [1614175529.9982] policy: auto-activating connection 'Wired connection 1'
Feb 24 15:05:29 ************.*****.** NetworkManager[727]: <info> [1614175529.9999] device (eno1): Activation: starting connection 'Wired connection 1' (2bbf67dd-db7b-3970-bebc-9dcc0bee92d2)
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0006] device (eno1): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0011] manager: NetworkManager state is now CONNECTING
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0017] device (eno1): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0023] device (eno1): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0029] dhcp4 (eno1): activation: beginning transaction (timeout in 45 seconds)
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0066] dhcp4 (eno1): dhclient started with pid 2999
Feb 24 15:05:30 ************.*****.** dhclient[2999]: DHCPREQUEST of 10.11.0.135 on eno1 to 255.255.255.255 port 67 (xid=0x14547754)
Feb 24 15:05:30 ************.*****.** dhclient[2999]: DHCPNAK from 10.11.0.1 (xid=0x54775414)
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0424] dhcp4 (eno1): state changed unknown -> expire
Feb 24 15:05:30 ************.*****.** NetworkManager[727]: <info> [1614175530.0457] dhcp4 (eno1): state changed expire -> unknown
Feb 24 15:05:30 ************.*****.** dhclient[2999]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 3 (xid=0xa3475f77)
Feb 24 15:05:31 ************.*****.** dhclient[2999]: DHCPREQUEST of 10.11.0.136 on eno1 to 255.255.255.255 port 67 (xid=0x775f47a3)
Feb 24 15:05:31 ************.*****.** dhclient[2999]: DHCPOFFER of 10.11.0.136 from 10.11.0.1
Feb 24 15:05:31 ************.*****.** dhclient[2999]: DHCPACK of 10.11.0.136 from 10.11.0.1
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1850] dhcp4 (eno1): address 10.11.0.136
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1851] dhcp4 (eno1): plen 16 (255.255.0.0)
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1851] dhcp4 (eno1): gateway 10.11.0.1
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1851] dhcp4 (eno1): lease time 432000
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1852] dhcp4 (eno1): nameserver '10.10.0.1'
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1852] dhcp4 (eno1): domain name '*****.**'
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1852] dhcp4 (eno1): state changed unknown -> bound
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1890] device (eno1): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1902] device (eno1): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1905] device (eno1): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.1907] manager: NetworkManager state is now CONNECTED_LOCAL
Feb 24 15:05:31 ************.*****.** dhclient[2999]: bound to 10.11.0.136 -- renewal in 182103 seconds.
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.2039] manager: NetworkManager state is now CONNECTED_SITE
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.2041] policy: set 'Wired connection 1' (eno1) as default for IPv4 routing and DNS
Feb 24 15:05:31 ************.*****.** NetworkManager[727]: <info> [1614175531.2044] device (eno1): Activation: successful, device activated.
Feb 24 15:05:32 ************.*****.** NetworkManager[727]: <info> [1614175532.5025] manager: NetworkManager state is now CONNECTED_GLOBAL
Feb 25 09:43:39 ************.*****.** NetworkManager[727]: <info> [1614242619.7174] modem-manager: ModemManager no longer available
Feb 25 09:43:40 ************.*****.** NetworkManager[727]: <warn> [1614242620.4743] error requesting auth for org.freedesktop.NetworkManager.wifi.share.protected: Authorization check failed: Refusing activation, D-Bus is shutting down.
Feb 25 09:43:40 ************.*****.** NetworkManager[727]: <warn> [1614242620.4743] error requesting auth for org.freedesktop.NetworkManager.wifi.share.open: Authorization check failed: Refusing activation, D-Bus is shutting down.
Feb 25 09:43:40 ************.*****.** NetworkManager[727]: <info> [1614242620.8516] caught SIGTERM, shutting down normally.
Feb 25 09:43:40 ************.*****.** systemd[1]: Stopping Network Manager...
Feb 25 09:43:40 ************.*****.** NetworkManager[727]: <info> [1614242620.8649] exiting (success)
Feb 25 09:43:40 ************.*****.** systemd[1]: Stopped Network Manager.
-- Reboot --
Feb 25 09:44:01 ************.*****.** systemd[1]: Starting Network Manager...
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4058] NetworkManager (version 1.10.6) is starting... (for the first time)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4058] Read config: /etc/NetworkManager/NetworkManager.conf (lib: 10-dns-resolved.conf, 20-connectivity-zorin.conf, no-mac-addr-change.conf) (etc: 10-globally-managed-devices.conf, default-wifi-powersave-on.conf)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4129] manager[0x55839c842050]: monitoring kernel firmware directory '/lib/firmware'.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4129] monitoring ifupdown state file '/run/network/ifstate'.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4316] hostname: hostname: using hostnamed
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4317] hostname: hostname changed from (none) to "************.*****.**"
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4319] dns-mgr[0x55839c833190]: init: dns=systemd-resolved, rc-manager=symlink, plugin=systemd-resolved
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4323] manager[0x55839c842050]: rfkill: WiFi hardware radio set enabled
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4324] manager[0x55839c842050]: rfkill: WWAN hardware radio set enabled
Feb 25 09:44:01 ************.*****.** systemd[1]: Started Network Manager.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4629] init!
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4630] interface-parser: parsing file /etc/network/interfaces
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4630] interface-parser: finished parsing file /etc/network/interfaces
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4630] management mode: unmanaged
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4633] devices added (path: /sys/devices/pci0000:00/0000:00:19.0/net/eno1, iface: eno1)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4633] device added (path: /sys/devices/pci0000:00/0000:00:19.0/net/eno1, iface: eno1): no ifupdown configuration found.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4633] devices added (path: /sys/devices/virtual/net/lo, iface: lo)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] device added (path: /sys/devices/virtual/net/lo, iface: lo): no ifupdown configuration found.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] end _init.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] settings: loaded plugin ifupdown: (C) 2008 Canonical Ltd. To report bugs please use the NetworkManager mailing list. (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-settings-plugin-ifupdown.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] settings: loaded plugin keyfile: (c) 2007 - 2016 Red Hat, Inc. To report bugs please use the NetworkManager mailing list.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] (-1668819712) ... get_connections.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4634] (-1668819712) ... get_connections (managed=false): return empty list.
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4797] keyfile: new connection /etc/NetworkManager/system-connections/Wired connection 1 (2bbf67dd-db7b-3970-bebc-9dcc0bee92d2,"Wired connection 1")
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4800] get unmanaged devices count: 0
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4801] manager: rfkill: WiFi enabled by radio killswitch; enabled by state file
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4802] manager: rfkill: WWAN enabled by radio killswitch; enabled by state file
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4802] manager: Networking is enabled by state file
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4803] dhcp-init: Using DHCP client 'dhclient'
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMBondDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMBridgeDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMDummyDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMEthernetDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMInfinibandDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4804] Loaded device plugin: NMIPTunnelDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMMacsecDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMMacvlanDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMPppDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMTunDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMVethDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMVlanDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4805] Loaded device plugin: NMVxlanDeviceFactory (internal)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4808] Loaded device plugin: NMWifiFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-wifi.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4810] Loaded device plugin: NMAtmManager (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-adsl.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4815] Loaded device plugin: NMWwanFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-wwan.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4838] Loaded device plugin: NMBluezManager (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-bluetooth.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4851] Loaded device plugin: NMTeamFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-team.so)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4861] device (lo): carrier: link connected
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4866] manager: (lo): new Generic device (/org/freedesktop/NetworkManager/Devices/1)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4881] manager: (eno1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.4894] device (eno1): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external')
Feb 25 09:44:01 ************.*****.** NetworkManager[753]: <info> [1614242641.7216] modem-manager: ModemManager available
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8542] device (eno1): carrier: link connected
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8547] device (eno1): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8552] policy: auto-activating connection 'Wired connection 1'
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8561] device (eno1): Activation: starting connection 'Wired connection 1' (2bbf67dd-db7b-3970-bebc-9dcc0bee92d2)
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8562] device (eno1): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8563] manager: NetworkManager state is now CONNECTING
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8565] device (eno1): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8569] device (eno1): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8613] dhcp4 (eno1): activation: beginning transaction (timeout in 45 seconds)
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.8753] dhcp4 (eno1): dhclient started with pid 1053
Feb 25 09:44:04 ************.*****.** dhclient[1053]: DHCPREQUEST of 10.11.0.136 on eno1 to 255.255.255.255 port 67 (xid=0x607974d)
Feb 25 09:44:04 ************.*****.** dhclient[1053]: DHCPNAK from 10.11.0.1 (xid=0x4d970706)
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.9114] dhcp4 (eno1): state changed unknown -> expire
Feb 25 09:44:04 ************.*****.** NetworkManager[753]: <info> [1614242644.9144] dhcp4 (eno1): state changed expire -> unknown
Feb 25 09:44:04 ************.*****.** dhclient[1053]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 3 (xid=0x60ac1e32)
Feb 25 09:44:05 ************.*****.** dhclient[1053]: DHCPREQUEST of 10.11.0.137 on eno1 to 255.255.255.255 port 67 (xid=0x321eac60)
Feb 25 09:44:05 ************.*****.** dhclient[1053]: DHCPOFFER of 10.11.0.137 from 10.11.0.1
Feb 25 09:44:06 ************.*****.** dhclient[1053]: DHCPACK of 10.11.0.137 from 10.11.0.1
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): address 10.11.0.137
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): plen 16 (255.255.0.0)
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): gateway 10.11.0.1
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): lease time 432000
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): nameserver '10.10.0.1'
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0147] dhcp4 (eno1): domain name '*****.**'
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0148] dhcp4 (eno1): state changed unknown -> bound
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0160] device (eno1): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0165] device (eno1): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0167] device (eno1): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0168] manager: NetworkManager state is now CONNECTED_LOCAL
Feb 25 09:44:06 ************.*****.** dhclient[1053]: bound to 10.11.0.137 -- renewal in 188164 seconds.
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0317] manager: NetworkManager state is now CONNECTED_SITE
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0318] policy: set 'Wired connection 1' (eno1) as default for IPv4 routing and DNS
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0320] device (eno1): Activation: successful, device activated.
Feb 25 09:44:06 ************.*****.** NetworkManager[753]: <info> [1614242646.0324] manager: startup complete
Feb 25 09:44:07 ************.*****.** NetworkManager[753]: <info> [1614242647.3381] manager: NetworkManager state is now CONNECTED_GLOBAL
Feb 25 09:49:21 ************.*****.** NetworkManager[753]: <info> [1614242961.6399] manager: NetworkManager state is now CONNECTED_SITE