hi, guys.
I have same trouble. but this method can remove it in my case.
make new key "HackFlags" as (DWORD 32) set value 0x600 as (Hex) in
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PnP\Pci\
and reboot.
ty
Well I'll be dammed! You sir are a genius!

All three GPU's running perfectly error free.
Just for my nerd interest what is the HackFlags doing here?

I have the same exact set up and same exact issue . Can you please tell me what the hackflags is ? I tried searching it and found nothing