While browsing for servers on the in-game server browser after refreshing, all servers may stop showing, including 'Recent', 'Friends' and 'Internet'. The problem is typically not fixed by returning to the main menu or by a single game restart.

I have also tried to rectify the issue using the launcher's server browser but it seems once the in-game one stops displaying servers, the effect is carried on to both browsers.

My internet connection remains stable through the issues, I can find a steam friend in game and attempt to "join game" through the steam UI, however this usually results in connection failed.

Typically rectified after a few minutes or a couple of full game restarts.