In regards to mem test, there always can go something wrong.
It kinda sorta is a memory torture test afterall.
Of course idk what you settings are, but if you run everyting in spec,
like it should, 3600mhz 1.35V and with 1800mhz infinity fabric.
Then that should basically be fine.
Update time:
After much testing I think it’s finally stable.
I got bored after about ~4d continuous testing and never restarting, yay!, I think I declare it stable now…
Thank you all for the suggestions.
It was the RAM in the end, it seems the old one was kinda bad even before the transfer to my STRX4 socket system but it doesn’t show up when it’s under cooler conditions.