@Angelo_Villasanta : @hipboi has confirmed what I suggested to you via discord; that your display resolution is too low. This means that forcing the resolution should work for you.
Here is the thing; your display advertises a native resolution of 800x480, so the kernel will pick THAT resolution, which is too low for Android, but the HDMI converter chip on it will accept ANY reasonable (i.e., standard-ish) resolution that you throw at it. So all you have to do, is force the rock960 to output a higher resolution, which SHOULD be possible using the kernel parameter I suggested to you previously, i.e.
video=HDMI-A-1:1920x1080@60e – or another resolution that matches the requirements, like (as @hipboi suggests as minimum), 1280x720.
If that doesn’t work, then you just add another parameter to override the display’s EDID:
drm_kms_helper.edid_firmware=edid/1680x1050.bin – or a different resolution, which really should be the lowest possible that meets Android’s needs, and of the same ratio as your display, and is in the list of hardcoded EDIDs. Your display has a ratio of 1.67, and the hardcoded EDID with the closest ratio is 1680x1050 at 1.6.
Here is a good reference for you: