Prototype movies have rounded corners at the bottom
The prototype movies force a rounded corner at the bottom making the video unusable. This should be exactly as the prototype with square corners on all sides.
Unfortunately also the video-File has rounded corners.
I wanted to use the simple animation for instagram story but the bottom corners under Mac OS Monterey are rounded. I used the record function in the XD preview window.
Cyrill Studer commented
When you record a video of prototype in XD on macOS the rendered video has the rounded corners of the OS-window. The Video file should be rectangular.