There is an issue in the preview rename feature when a title of an episode is too long. It won’t display anything. The log says
Request Failed. GET /api/rename: The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.
Due to this issue it won’t display anything until I remove the file. This was the workaround I used to rename the rest of the files.