I'm experiencing the same issue. In the middle of a reinstall now.

Having a similar problem, as soon as 6.1.4a was live, I could not even get to the server selection screen before being booted out. I have turned off Vsync I have turned off Game Bar I have run the game in Admin

As soon as 6.1.4a was available and the servers went back up, I have not been able to log into my game. I just returned YESTERDAY after being gone since 2012. Even got my wife into it and she can't play it on her off day rn I have turned off the Game Bar I have turned off Vsync I have run the game as admin 24 hours before I request a refund on my subscription > EDIT: I'm going to reinstall to see if it helps. I just installed yesterday so this is really fun and awesome.