It looks like Plex is doing something weird in the web interface. Despite the playlist tracks being listed in a text format, using the browser search (CTRL-F) cannot find any of the songs in the playlist. But weirdly, it can locate the track times to the right of the track names and artist.
Is there any way to search a playlist? This is kind of crazy that Plex is doing something weird with the track and artist names to make them unsearchable using the web browser built in text search.