Try change the disp_mode option in the file /boot/armbianEnv.txt to the resolution of the screen
If it doesn't work:
- ls /sys/class/drm/
- cat /sys/class/drm/*/modes
The first one is to discovery the exact name of your display connection. In my case (orange pi pc connected via hdmi) it appears card0-HDMI-A-1, so the name of display connection is HDMI-A-1.
The second one is to check the available resolutions from your display device.
In addition to change disp_mode, add a line with extraargs to the file /boot/armbianEnv.txt.
Here is my example, adapt it to your case:
extraargs=video=HDMI-A-1:1920x1080@60
Note: the refresh rate does not appears in the command "cat /sys/class/drm/*/modes"