My guess is your processor is unstable, which can be caused if you’ve undervolted, overclocked or manufacturer error. If not I would say it’s something with your Memory like a bad component.

Maybe turn on undervoltage protection in bios and see if that helps, turn off XMP if you have it enabled and see if that helps. If not I would RMA CPU or at least contact INTEL support and ask questions and they might be able to help.

If you play in 4K, there is negligible difference in games as it’s mostly GPU bound but I feel like 7800x3D is the better choice all-round