Yeah, had the same problem with two aftermarket fairings. They don't fit well at all. On one I could barely get the base of the lock to mount. Looks like the cover isn't fully seating which is exactly what I experienced. You could take a dremmel to either the cover or the tail fairing where it rubs so that it'll seat fully.
Bottom line, it's not fully seated in the back. You can see it in your video that it's not flush. You could always just press it in but then it'll be hard to open without prying. My suggestions are either modify it to fit or press fit it.