CPU overheat issue

[noble relic]

I have a 5600x and a 360 lian li AIO. I've been using the system perfectly fine since I built it late 2020. I more or less stopped using my PC for gaming for about 2-3 months and it was mostly left off while. I returned to find my CPU temps were high for no apparent reason (idling at ~45c when originally idling in low-mid 30s and going up to between 70-90c during gaming). the system was cleaned of dust about 2 months prior to setting it aside and it still looks clean now. I'm thinking about trying to reseat AIO (can still feel liquid being moved through tubes) and re-paste CPU, but wanted to see if anyone had any other thoughts on what the issue could be?

[foggy robin]

you are on a good track, re-applying thermal paste is a good start

[open kelp]

could be alot of air in the loop, just let it spin for a while and put the rad above the pump