This is not related to the OS, but I thought that some Zen2 users have encountered a similar issue and/or have a solution/workaround for it.
CPU: Ryzen 9 3900
MB: Asus Prime X570-Pro, latest BIOS, AGESA 188.8.131.52
RAM: 2x 16G Crucial Ballistix DDR4-3200 (XMP) at 1.35V
What I still need to check: Ryzen Memory Timing Calculator (Windows)
When running on the XMP frequency and voltage, the system has trouble booting and stays at blank screen with uninitialised keyboard, needs a few resets until it starts through. Eventually it boots.
Going back to DDR4-2666 at 1.35V helps, the system boots correctly on 1st try and generally seems to be a little more stable.
A quick web search shows that some users have similar problem and it is not a pure Asus problem.
Some BIOS have a special "Boot RAM Voltage" option which seems to help in some cases by increasing it, but mine doesn't.
Note that I do not have errors on MemTest (EFI version from AUR) running DDR4-3200.
Maybe Zen2 with current BIOSes is very picky on dual-bank RAM.
I don't know.
System stability seems fine so far, although mprime with AVX2/FMA3 crashes within seconds, which might be an mprime issue though.