I have my motherboard (ASRock X470 Gaming ITX/ac) on latest BIOS 3.30 (AGESA 1.0.0.1) and reset BIOS and cleared CMOS. When I install Ryzen 3700X, I cannot boot into Windows. Issue resolves with Ryzen 2700X.
Try looking to AMD Reddit. I have found some good troubleshooting for similar motherboard CPU combos in there.
