I agree with Lutfij,
that your power supply mfg and model is needed. In addition, I recommend that you list all your system specs. With that said, the fact that the crashes stopped once you turned off XMP, makes me assume that the crashes are related to your memory somehow. Is your BIOS updated to the latest version? Do you have the chipset updated (amd) or management engine updated (intel). Important
: Are your RAM chips installed in the slots that your motherboard's manual specifies? I once had an AMD B350 chipset motherboard which had two 16GB 2400 MHz RAM installed, running at 2133 MT with XMP off. Once I enabled XMP, the computer was completely unstable, and practically unuseable. I then realized that my RAM was in the wrong slots, but hadn't been a problem until I enabled XMP. At a minimum, I would update the BIOS, while adhering to the notes listed in the BIOS page. And then I would locate the manual and verify that the RAM was in the proper slots before
re-enabling XMP. That's what I would do in your situation.