MasterClass metadata

This condition should clear after a properly executed Plex dance.
If it doesn’t, then you might have introduced additional folder levels, or have pointed the library directly at this one show. Either is bad and won’t work.
Please post the first ~20 lines of the Plex media info XML from one of the episodes – as they currently are.

Then take a look into the properties of your library and note down which folder is appearing currently on the tab “Add Folders”.

Please do also verify that all the video files are valid and working when played in a regular video player app.