DetectMode not working

When I set DetectMode in Registry to 2 (DWORD), nothing changes. I expect to have a 1920x1080 resolution but it only does 800x600 as described by CXScreen and CYScreen.

Whats up with that.

I cannot test different settings, because Warmboot is not working.

What version of the image are you using?
Did also added EdidSlaveAddr parameter (dword set to 0x50) to the registry?
You can get more information by enabling serial console.
Enter the bootloader menu by pressing space on serial terminal (1152008N1 no flow control on UARTA) and then the console by pressing ‘x’.
set dbg.serial 1
save dbg
Now you should see some message if EDID screen is or isn’t detected.
What do you mean with “warmboot is not working”?