Thanks for the feedback. So I purchased the Ruipro Ultra-Slim HDMI Active Optical Cable 4K 60Hz 4.4.4 (10M). I made sure to align the source end with the source for proper direction but am still experiencing the same issue. I can't be the only person running cable from the front of the room to the overhead projector. Did I pick the wrong cable?
No you did not, but you might need a voltage inserter to power the cable. I'm using a 35' Ruipro cable, but I use a
Legrand Voltage inserter. I have had no problems at all. It has been rock solid stable. If you problems continue after that, then either the sending unit or the receiving unit is faulty and needs to be replaced. You seem to have eliminated receiver and peripherals, so that leaves the projector.
The reason for using a voltage inserter is that the power draw of all types of active cable exceeds the HDMI spec. Some units work with it and some don't.
With the Ruipro cable and the voltage inserter, I have zero problems.
If you have trouble after that the most likely unit at fault is with your projector, which would likely mean a bad HDMI board. The cost of replacing that would make it wiser to go for a new projector. Unfortunately HDMI failures are far too prevalent.