So I've been experiencing some really bad FPS drops and lag when playing poe, csgo and wow. I really don't understand why it is this bad. Looking at temperatures everything is under 50 degrees except for my GPU that is sitting at around 70 degrees.
To solve the problem I'll have to restart the game but that is only temporary.
Things I've done to try and fix this is getting better cooling for my PC, changed cooling paste on CPU and added a few fans.

PC specs
Ryzen 5 3600
RTX 3070Ti (dont know exact model)
32 gb RAM 3600MHz

If its temporarily fix after restart, maybe a fresh os might fix the issue. But that could be a lot of work, if you have personal files and what not.
But its looks like software issue. Have you installed any programs recently? Could be causing the issue.