export creating out of place frames
After exporting a video from FCPX, my clips almost always have a glitch in the top left hand corner of the frame. This rarely appears in my timeline on FCP, but always ends up showing up in my exported file. What's the cause of this problem? How do I go about fixing it? I've attached a still frame to this message to better visualize what I'm talking about.
MacBook Pro 13″, macOS 10.14