Question How do I fix input not supported on my RX 6600 and Acer SB230 when it boots up but then my GPU works fine once I get into Windows 10?

[MagicalJester]

I have been going through this issue for about two years and it still has not worked at the slightest. The problem with my system was that ever since I changed my graphics card from an RX 570 to a XFX RX 6600 graphics card on my Acer SB230 monitor. Ever since I upgraded my graphics card to an RX 6600, it kept saying "input not supported" on the boot screen, then, suddenly works once I get into Windows 10. This is a massive issue as I cannot access my BIOS because I cannot obviously see what I am doing with my computer. I had to borrow my mom's monitor (which is an older monitor) to fix this issue. This is beyond ridiculous that I can use every other monitor but Acer. What can I do to get this issue fixed. I already enabled CSM (Compatibility Support Module) and many other things but to no avail. Can anyone help me please?

 

[MagicalJester]

Do I have to list the full specifications of my computer as well?

 

[CountMike]

Do I have to list the full specifications of my computer as well?

Issue is that monitor can't detect GPU output frequency and or resolution until driver in windows is active and informs windows about those values. check monitor's OSD options if you can set HDMI as default input.