Hello @vix,
You can try to force a specific resolution to be valid.
This is done via a kernel argument:
sudo fw_setenv tdxargs video=HDMI-A-1:1920x1080
This does not always works, as the available resolutions are limited.
Another alternative would be to load an external edid firmware.
This approach has some limitations which I outlined in the following post: Inject custom edid - #10 by bruno.tx
Best Regards,
Bruno