Nothing we can do about it. There is no way for a display to signal to a source whether it’s in full-range or limited range mode. Please see here:
You haven’t explained why you want to output full-range video. We recommend you use limited range. We also recommend you set your GUI resolution to 1080p. Vero will still output 4k videos as 4k if you set Adjust refresh rate to On start/stop in Settings->Player->Videos.