PC Crash every game - with possible solution

I recently upgraded my GFX card to an Nvidia RTX 4060. Since then HS has been very unstable, either crashing the game or my PC almost every game. I have no issues with Path of Exile 2, which I have also been playing, and that is far more demanding on the system

I’ve tried quite a few things, and then today changed the Graphics settings from Quality: High to Medium and Frame Rate: High to Low (didn’t experiment with other combinations). And no crash for the past few hours. I should also point out, I have previously tried different resolutions and full-screen / windowed which made no difference

Wondering if anyone else has a similar experience, or some insight on what the actual issue is and how to fix it?

Some technical details:

Event viewer had this for the PC Crash:

Reported by component: Processor Core
Error Source: Machine Check Exception
Error Type: Cache Hierarchy Error
Processor APIC ID: 2

and this for the Game crash, pointing to Unity:

Faulting application name: Hearthstone.exe, version: 31.4.3.18231, time stamp: 0x6721598c
Faulting module name: UnityPlayer.dll, version: 2022.3.52.8444, time stamp: 0x67215bf9

I’ve uninstalled and reinstalled [battle.net](http://battle.net) & HS. Uninstalled all the MS C++ distributions which get installed for Unity. Video driver is newly installed

I have had other instability issues with this PC over the past few years (Ryzen 5 3600 with MSI 450 Tomahawk)