Thank you so much! I had the same issue + random reboots while playing games (Kernel-Power 43 BugcheckCode 278 in the Event Viewer) on MSI B450 Tomahawk Max, Ryzen 3600, MSI GTX 780Ti & Corsair 16GB 3200MHz Vengeance LPX Black. I've been trying to fix this problem for days now (bought new PSU, thought that my GPU is dying, tested RAM with memtest, reinstalled Windows etc etc) then I found this topic. It was bios all along! I coudn't believe it. Flashing v30 bios fixed the reboot and driver issues for me.
The only thing I'm concerned about is that my GPU is still running at PCI-E x8 3.0 instead of x16. PSU swap and v30 bios didn't help with the bus interface issue so it has to be the bios, drivers or GPU. My bet is on the bios. It's a minor issue tho. It won't affect me that much. Maybe 1-2 fps here and there. Who cares. Hopefully the next stable bios will fix it for me. I will report this problem to MSI, but I'm sure they know about it already.
I can finally enjoy my new build
