I have come across an issue with adding videos in iOS 12.4.7/VLC v3.2.11 iPod Touch v6.
When I add video files while connected to iTunes 12.8.2.3 File Sharing while an already loaded video file is playing, some of the newly added video files don't appear in the Video page, but do appear in the iTunes list.
Quitting the app does not force a rescan, nor makes them appear. I have been able to rename the file in iTunes File Sharing, then quit the app and reload, then the "hidden" video file appears in the Video selection when the app loads again (I can rename the video back to what it was).
I have not tried the "Force VLC to rescan the media library" in Options to see if this discovers those "hidden" files.