CPU MS spikes massively, PC freezes (Linux)

So, it appears to happen in random intervals that the CPU MS in game spikes heavily (to around 5000 MS) which causes not only the game to stutter but the complete PC to stutter, including Discord. Sometimes it fixes itself after a few seconds, but if it happens in loading screen, I can only shutdown the PC, as it seems to freeze completely.

Specs:
CPU AMD Ryzen 9 5900X
16 GB RAM
RTX 2080 TI

OS: Linux Bazzite

If I need to supply additional infos, pls lmk.

After looking at it a bit more, it seems to some sort of memory leak? I have 16 GB of RAM, which isn't insane, but should be enough. Regular usage (Firefox open, various software) is around 6.6 GB of usage. Immediatly after starting PoE it goes up to 12 GB and then slowly, over the course of 3-4 hours or so inches higher and higher. And after I get over 15 GB, the CPU MS can suddenly spike heavily. If I restart the game, it is fixed for a few hours.