Prometheus hooked to HD20 optima projector issues

Hi all, I have hade my Prometheus box for a couple of years now. I have just recently decided to hook it up to a projector. I have run a 10 meter hdmi – fairly cheap not a pricey one! This I have put through a sound bar. Now when I wire direct from Prometheus direct to projector no issues. However once I go via the sound bar that’s when I seem to get issues. Sometimes it’s not bringing up the kodi screen but a blank pink screen? Any ideas?
Martin