We have been running a server for the past few months with very few problems. However, just recently, players have suddenly began being unable to join. When they try to connect, it sits on the generating world screen for a really long time, and then it says "[player] left the game" in the in-game chat. This is affecting multiple users, both those on and off of the whitelist, but the same players are able to join using different accounts on the same device. This occurs seemingly randomly; for example, a player was able to join this morning but is now unable to despite no changes to the server configuration.

On the console, it registers that the player has joined, however this doesn't come up in-game.

This issue has now started to affect other servers on the same machine.