I was having the same problem with the same hardware, like @plindberg I changed the RAM clock speed to 2666Mhz and this seems to have fixed the issue (although its only been a few hours), I will continue to monitor my system, but for anyone else like @sagman and @Mohrpheus78, these are the steps i took to adjust the memory speed:
Enter the UEFI (press F2 during boot)
Advanced
AMD CBS
UMC Common Options
DDR4 Common Options
DRAM Timing Configuration (click accept on the warning page that pops up after this)
Memory Clock Speed
Change the memory clock speed from "Auto" to 1333Mhz
Press F10 to save and exit