[SOLVED] Hyper-V black screen and blocking cursor for ~10s on Win logon screen

[spamaps]

After installing Hyper-V - logon screen always turning fully black (only cursor is visible) for ~10s and stops cursor when I try to click something or use keyboard.
Even when I login to Win account by some miracle (and ~5min of waiting) same issue showing up, like on logon screen.

Event viewer not pointing out any cause of this, just some generic info about problem with window manager and logon screen (stops working).
Edit: I found only one type of error about Hyper-V - "Hypervisor failed to properly synchronize TSC across logical processors (Max delta: 71903523, Min delta: 0)."

Safeboot working fine but normal boot with 0 apps on startup gives same. After uninstalling Hyper-V everything comes back to normal.

SVM is turned ON in BIOS and I tried latest stable BIOS and beta.
Also latest drivers for devices from MOBO website + chipset drivers from AMD
Same Windows (without UEFI) and installed software + Hyper-V working fine on old build with AM3 socket.

Specs:
UEFI Windows 10 Pro v1803 build 17134.48
Asrock AB350 Pro 4
Ryzen 2600
8GB RAM 2933 (XMP profile)
GTX 1050

List of installed software - https://pastebin.com/raw/huCpxWKC


Any advice how can I fix this or whats causing this problem?

 

[spamaps]

Few hours digging in the BIOS settings and I found reason - CPU overclocking. Even if it's 25 MHz (one step in BIOS) lagging cursor and black screen still showing up, but for shorter amount of time, ~2s instead of 10. Turning OC to "Auto" (aka disabled) and Win Hyper-V is working...

Without Hyper-V I was getting 3.9 with good temps and that OC passed stress testing for about 10h. So I assume it's still something that should be fixed by BIOS or Windows update.

 

[spamaps]

For those who had same issue, there is BIOS update 5.00 from ASrock website. Both CPU overclock and Hyper-V now working correctly.
I don't know if this is included only in this update because I missed one version before 5.00.

Also Windows had update so this is current version:
UEFI Windows 10 Pro v1803 build 17134.165

I'm not 100% sure if that issue was based on Windows or BIOS but it's working