Specs:

OS: Windows 10 64bit

CPU: Intel i7-10700

GPU: GIGABYTE Geforce RTX 3070

32gb DDR4 RAM

mobo: TUF GAMING Z490-PLUS

psu: DeepCool PM750D

Lately my PC has been hard crashing during gaming sessions. No BSODs, just freezing that requires a manual reboot. Seems to happen at random, but more often during loading transitions? The GPU has recently been serviced (was still under GIGABYTE manufacturer warranty, they didn't say what repairs they did but I'm guessing thermals), so I'm almost certain that isn't the issue, temps are also much better after said repairs. Temperatures are, however, quite unstable on the CPU side, and I've noticed they can pretty quickly reach the 90-100 degree threshold under load. I'm fairly positive this is the cause of the crashes, but I guess what I'm asking is whether there's any way I can confirm that the CPU is the issue? Or find whatever's causing it to overheat so much? System-side, I've done everything short of reinstalling my OS, including sfc, ram and drive health checks, malware scans, etc. I'm fine to replace the MOBO and CPU, I just don't want to replace them and then find that I'm still getting crashes. Any help you can give is greatly appreciated.