Could you provide full system specs please, and if possible, your monitor setup and how they are connected? That said, I vaguely remember hearing about this being some issue with certain DP (or was it HDMI) based monitors unable to go into BIOS on certain systems. I forget the fix and the exact issue, but it may be worth looking into.
Also, just to be clear, you are able to boot into Windows 10 fine and the computer works from there, but you are unable to go into the BIOS setup?
Sure.
CPU: AMD Ryzen 5700X
MB: Gigabyte Aorus Master X570S
RAM: 64 GB Silicon Power Turbine Xpower DDR4 3600 (4 x 16 GB)
Graphics: EVGA GeForce RTX 3050 XC GAMING
Sound: Sound Blaster Z SE (in PCIe x4 slot)
PSU: Seasonic Prime TX-750
Drives: Samsung 980 Pro 2 TB, Samsung 870 EVO 4TB, Samsung 860 EVO 1 TB, Asus Blu-ray drive, Plextor DVDR
CPU water cooler: CORSAIR iCUE H115i RGB PRO XT
Case: Corsair Obisidian 450D
Monitors: Samsung C24FG70 24" (x2)
Correct, I am able to boot into Windows 10 fine, but rebooting into the BIOS won't work. Monitors are plugged in through displayport and I think they are only DP 1.2 because they are 1080p monitors. The other issue I have is the video card only runs in PCIe 4.0 8x mode instead of 16x mode, even though nothing is plugged into the 8x slot. Yes I did try taking the sound card out of the 4x slot, made no difference. I was thinking about contacting Gigabyte and that these may be issues with the board, but thought I'd ask her first.