Thank you for answer. Honestly, I didn't make any changes because nobody on the net told to change the bios. I once broke a motherboard because of bios changes. That's why I didn't change anything. I looked in the bios I think it had something to do with the power settings. I'll look after work.
This is starting to get ridiculous. I have the same gigabyte z590 ud ac motherboard, 11600k and MSI rx6600 Mech 8gb graphics card. I also did some of what you said (except Bios update and CMOS cleaning) I couldn't get a solution either. I can't send it back because I ordered from abroad. I...