I've casted two UHD movies from Google Play Movies and both times I noticed intermittent flickering of a solid yellow rectangle at the bottom-left of the screen. It appears at random times and only lasts half a second. When the yellow rectangle appears I notice that it also distorts whatever is on the screen within that half second as well.
Have any of you experienced this? I will try to take a photo/video this evening.
In terms of my setup, I have a P75-C1 and am currently on the newest beta firmware. However, I've experienced this issue with the new firmware and the one just prior to it being updated. I was casting the rented UHD movies from the included tablet.