I checked back on the reddit thread I posted in my original post and it seems that a bunch of people are saying this is still happening. Even after replacing the PSU. I'm starting to think it's some kind of fault with ASUS components and RTX 30 series. I will still try changing the PSU when I get the chance to buy one. I'll keep you updated though.PSU might not like idle loads. I was going to tell you all about how Ryzen react at idle but it doesn't apply as you have Intel.
Could just be showing its age.