Troubleshooting Issues With Video Playback On Films And TV App

I've been having trouble with the Windows Films and TV app on my PC. Normally, I'd use it to open video files, but recently, it seems that the option to set it as the default app for opening videos has disappeared. Despite reinstalling the app, the issue persists. Admittedly, I don't often play videos on my computer, so I'm not exactly sure when this problem started. Any suggestoins on how to fix this would be greatly appreciated!