I have been driven insane by this glitch for months,I just ignored it as it doesn't happen all the time but I make YouTube videos so I want to be perfect.
I have no idea what the name of the problem is which makes google searching the problem so much harder but I will describe the problem as best as possible and I even have a picture!
I use multiple layers in my videos as I do trolling videos which use gameplay and a facecam. In 1 frame out of 1 thousand the video from the layer above replaces the gaming gameplay for 1 frame and goes back to normal! It drives me nuts and you see it on the final rendered video and it is so annoying! Here is a picture