Changing Display resolution on Android

Hello, I have been trying to change the hdmi display resolution on dragonboard 410c. It runs at 1920x1080 by default and works fine on my HD monitor.
I have a 10 inch 1280x800 hdmi monitor and it doesnt work with DB410c.

I tried changing the resolution by adb
adb shell wm size 1366x768

and got the following
~$ adb shell wm size
Physical size: 1920x1080
Override size: 1366x768

still the display doesnt work. I think the actual " physical resolution" needs to be changed.

Kindly help me, thanks in advance