Crashes and lag when running 2 TBC clients

I have 2 wow accounts and I’ve often been running them simultaneously since the launch of Classic. Lately when I do this, the instance of the wow client I have running in the background will randomly crash without any error messages. I’ve also had trouble playing any kind of video (twitch&youtube) while running 2 clients without crashes and severe lag.

My wife is experiencing the same on her Pc. We both recently switched to 3080s and our drivers are the newest ones and we’ve done a lot of fiddling with the video settings in wow but no luck. We’ve also tried repairing and re installing wow but this hasn’t helped either.

If anyone else has had this and know of a way to fix it I would really appreciate some help.