I assume that it is a feature that any folder that itself contains a VIDEO_TS folder shows in Media player not as a folder but as content (blue dot instead of folder icon). This makes sense generally, but if you happen to have a folder that contains both playable media files and a VIDEO_TS folder, those other files are effectively hidden from the Media player UI.
Would recommend that the blue dot appear only if the folder containing the VIDEO_TS folder doesn’t also contain other playable media.
I’ll often have a parent folder with a movie name; in that folder is the VIDEO_TS DVD rip along with a Handbraked .mp4 file (or multiple files in the case of TV shows).