UNO Q hardware encoding via USB camera

I have been trying for a few days now to get h264_v4l2m2m encoding to work with a USB camera. Up to now I have had various strange outlier sucesses, but the only sucess that I can say is for certain is, that hardeware encoding only works under 800x600 it crashes if the resolution is set higher than 800x600. Has anyone come across this issue? is there a fix for it?