Hello!
After I upgraded to the new version 2021.0.11 I have the same problem - before everything was okay and I could log in without any problems.
I hope you can fix that bug soon- Thanks!
Greetings
John

P.S.: If you still do need more logfiles please contact me- no problemclient.log

Other users have reported it is due to a bad dns config on their machine https://forum.faforever.com/topic/2616/login-issue/11?_=1633862387156