Hi,
I have been having this problem after the newest content patch.
My bfs computer totally freezes after gaming for a short while. (I would say 5 to 30min max).
My game and chat window freezes, but I can hear the voices that come from other group members being in combat or mobs that are nearby, hitting me or other players.
I get this “beach ball” rolling and then it freezes.
Only thing that helps for it is force closing game and restarting it.
But then again, minute or 5 the same thing appears.
It REALLY does bother and I really can’t play the game 
His computer is MacbookPro, Mojave OS from 2018. 2.3ghz i5, 8GB memory.
Could updating OS help somehow?
I do not run any addons on this computer.
I tried the scan and repair.
I deleted the interface and such folders and relogged.