HDMI resolution adjustment

I have recently purchased CM3 IO board with radxa cm3 module , and followed the procedure to install android 11 on it . the OS installed but the UI is all stretched when i see it on a tv monitor, its looks like android mobile OS , i have tried change the resolution but its not working .
using adb i get the resolution as 8001200 , i treid to change it to 19201080 through adb but still no change
could you help me with fixing this resolution issue ?
Thanks