I actually had a similar issue, but within the Samsung Video Player itself. When I would play any video, the screen would kind of flicker on/off or have horizontal lines on it. That started about the time I was playing with a Miracast receiver. Didn't have any issues with any other video player. The video player had also started giving me a message like, "cannot play while on call" or something. Clearing RAM/Apps fixed that. But it took a reboot to resolve the video player issue.