Thanks, that's interesting.
I used to have a lot of video card output switching off a year ago, and disabling VT-d in the bios fixed the problem (until iCUE caused it again), VT-x is enabled.
Would you mind disabling VT-d and enabling VT-x to see if crashes occur?
Also the fact that you're using the motherboard sound card is interesting, I used to have much less crashes during the time when I didn't use the DP sound, and used the motherboard sound card instead.
I also tried disabling daisy-chaining and using only one monitor, didn't help for the crashes back then (HDMI and DP).
Also, the answers to my own questions:
1. I tried 4701, crashes happened with it as well, so I updated to 4801 (BETA bios), didn't change until I disabled VT-d.
2. 4 x KHX1866C10D3/8G = 32GB
3. VT-d is OFF, VT-x is ON.
4. 398.36 - Geforce Experience is installed.
5. Using sound from DP.