Pc shuts off every time I turn it on

My pc that I built in 2021 has been running into some issues. Every time I turn it on, it turns off - I think it is a heating problem (there was one time it said it was over 100 on BIOS but after dusting it off with compressed air it says on OpenPC that it’s 88 C).

My suspicion is that I need to reapply the thermal paste or something is wrong with the cooler.

I believe I have the Ryzen 5 3600 CPU and my cooler is a corsair AIO cpu cooler.

I have been grinding hello kitty island adventure if that is relevant 😅

Does anyone have any insight into this? Or can help me? Thanks in advance!