i tried sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf changed to 2 from 3
tried this drivers - DPKG error while installation bcmwl-kernel-source on ubuntu 16.04 - Ask Ubuntu
also the result of sudo lshw -c network
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: enp2s0
version: 10
serial: c8:5b:76:81:8c:65
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=6.5.0-35-generic firmware=rtl8168g-3_0.0.1 04/23/13 latency=0 link=no multicast=yes port=twisted pair
resources: irq:18 ioport:4000(size=256) memory:d1204000-d1204fff memory:d1200000-d1203fff
*-network
description: Wireless interface
product: Wireless 3160
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlp3s0
version: 93
serial: e4:02:9b:14:e9:f2
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=6.5.0-35-generic firmware=17.3216344376.0 3160-17.ucode ip=192.168.78.112 latency=0 link=yes multicast=yes wireless=IEEE 802.11
resources: irq:52 memory:d1100000-d1101fff
sudo dmesg -w (log)
[18978.245121] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[18981.807520] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[18981.807544] wlp3s0: 80 MHz not supported, disabling VHT
[18981.812504] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[18981.819901] wlp3s0: authenticated
[18981.826168] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[18981.831239] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[18981.845375] wlp3s0: associated
[18981.978584] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[18985.443066] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[18985.443094] wlp3s0: 80 MHz not supported, disabling VHT
[18985.447715] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[18985.451554] wlp3s0: authenticated
[18985.454089] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[18985.459222] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[18985.461382] wlp3s0: associated
[18985.542762] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19000.197511] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19000.197537] wlp3s0: 80 MHz not supported, disabling VHT
[19000.203097] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19000.210466] wlp3s0: authenticated
[19000.218251] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19000.223494] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19000.225240] wlp3s0: associated
[19000.288454] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19003.756213] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19003.756262] wlp3s0: 80 MHz not supported, disabling VHT
[19003.761050] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19003.763895] wlp3s0: authenticated
[19003.766271] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19003.770764] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19003.781908] wlp3s0: associated
[19003.899468] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19007.399175] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19007.399213] wlp3s0: 80 MHz not supported, disabling VHT
[19007.404551] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19007.407534] wlp3s0: authenticated
[19007.414274] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19007.419310] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19007.421490] wlp3s0: associated
[19007.456377] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19026.197523] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19026.197548] wlp3s0: 80 MHz not supported, disabling VHT
[19026.203378] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19026.206584] wlp3s0: authenticated
[19026.210439] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19026.215307] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19026.217407] wlp3s0: associated
[19026.298724] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19029.816393] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19029.816442] wlp3s0: 80 MHz not supported, disabling VHT
[19029.821792] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19029.826373] wlp3s0: authenticated
[19029.830488] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19029.835590] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19029.837538] wlp3s0: associated
[19029.881990] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19033.367414] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19033.367438] wlp3s0: 80 MHz not supported, disabling VHT
[19033.372480] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19033.381058] wlp3s0: authenticated
[19033.382554] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19033.387717] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19033.389790] wlp3s0: associated
[19033.466031] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19036.956392] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19036.956439] wlp3s0: 80 MHz not supported, disabling VHT
[19036.962360] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19036.969498] wlp3s0: authenticated
[19036.970922] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19036.976087] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19036.987180] wlp3s0: associated
[19037.050016] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19048.195157] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19048.195180] wlp3s0: 80 MHz not supported, disabling VHT
[19048.200368] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19048.203225] wlp3s0: authenticated
[19048.206700] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19048.211217] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19048.222255] wlp3s0: associated
[19048.313992] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19051.820738] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19051.820786] wlp3s0: 80 MHz not supported, disabling VHT
[19051.826407] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19051.833381] wlp3s0: authenticated
[19051.834776] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19051.839869] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19051.841945] wlp3s0: associated
[19051.897907] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19055.380491] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19055.380536] wlp3s0: 80 MHz not supported, disabling VHT
[19055.386158] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19055.393256] wlp3s0: authenticated
[19055.394733] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19055.399838] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19055.402184] wlp3s0: associated
[19055.531270] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19058.995536] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19058.995561] wlp3s0: 80 MHz not supported, disabling VHT
[19059.000572] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19059.008360] wlp3s0: authenticated
[19059.010740] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19059.015943] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19059.018248] wlp3s0: associated
[19059.093398] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19070.202056] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19070.202084] wlp3s0: 80 MHz not supported, disabling VHT
[19070.207379] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19070.211129] wlp3s0: authenticated
[19070.214794] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19070.221107] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19070.232394] wlp3s0: associated
[19073.071978] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
[19076.572675] wlp3s0: authenticate with b6:e7:a7:14:b0:27
[19076.572723] wlp3s0: 80 MHz not supported, disabling VHT
[19076.577602] wlp3s0: send auth to b6:e7:a7:14:b0:27 (try 1/3)
[19076.582643] wlp3s0: authenticated
[19076.590874] wlp3s0: associate with b6:e7:a7:14:b0:27 (try 1/3)
[19076.595978] wlp3s0: RX AssocResp from b6:e7:a7:14:b0:27 (capab=0x411 status=0 aid=1)
[19076.597650] wlp3s0: associated
[19076.678867] wlp3s0: Connection to AP b6:e7:a7:14:b0:27 lost
This is the log i got while it disconnected automatically even after trying all the above steps.
@Storm
@Aravisian