I wonder if the monitor reports these modes as fine, but the card can not drive them, and bails out instead of falling back on other modes. Can you please run: sudo ddcprobe > ddcprobe.txt and attach the file ddcprobe.txt?
I wonder if the monitor reports these modes as fine, but the card can not drive them, and bails out instead of falling back on other modes.
Can you please run:
sudo ddcprobe > ddcprobe.txt
and attach the file ddcprobe.txt?