I ran Memory Diagnostic Tool 2 times, as far as I understand it should show any discrepancies and should fix them automatically.
No, if it finds errors it means that the RAM is having errors which usually means it’s faulty. It can’t fix anything. With the two crash errors you’ve had, I would suspect the CPU.
It looks like RAM from the dump files. First try setting the RAM to 5600MT/s or slower as that is the highest officially supported by the CPU and higher speeds overclocks the memory controller in the CPU.
If it still crashes use the machine normally with one stick at a time and see if only one of them cause crashes.
As this is intermittent, you could try a Memtest86 as well, but be aware that memory testers are not super reliable with DDR4 and newer so a clean scan doesn’t mean anything. No false positives.