Thanks for the comments. I did bios update based on the youtube guide above, to the latest version (F21, release date: 2022/11/15):
https://www.gigabyte.com/Motherboard/B660M-AORUS-PRO-AX-DDR4-rev-1x/support#support-dl-bios
I guess, I did the bios update correctly. I kept CPU/RAM on board and...