I am making English titles for a show that was originally broadcast in Japanese. There is a part of a motion graphic in the footage that I need to cover up to hide some weird English from the original broadcast version. To do this I've covered the spot in question with a black matte that has been masked. However when I export the video I get interlaced lines over part of the graphic that I want to keep. I've attached a file showing the issue. You can see how the diagonal yellow bar is partially blocked.