Your source i loooed at and a diff method worked:
came here to give the same solution knowing it would be a problem for many people if it happened to them.
If proton freezes and crashes it messes up the connection with pvpn-ipv6leak-protection still running even if you restart the computer.
I did pretty much the same thing to solve it.
I used this command in terminal to show the connections
CODE: SELECT ALL
nmcli connection show --active
this was still running pvpn-ipv6leak-protection
I ran this to stop it
CODE: SELECT ALL
sudo nmcli connection delete pvpn-ipv6leak-protection
Internet immediately star
On mobile no au5ocorrect sorry