21:15:04 up 1 day, 24 min
So I think I can safely tell that all the issues are resolved. Server is up for more than a day, transcoding works great, no errors in logs.
Maybe this was a bug in EDAC, and I didn’t have to swap modules, because I have same as in the beginning inside now, and they work fine, maybe some dirt got it’s way inside DIMM slots, maybe something else, but it finally works.
Thanks everyone.