A few upgrades ago (I’m currently on Ubuntu version 1.22.2.4282) Plex stopped downloading metadata for tv shows. As far as I can tell, this is across all of my tv shows recorded since then and some before. I believe I had metadata for the previous ones, but it appears to be lost. All that displays is the data of the episode with no description. Here are a few examples of my file naming/structure:
$recordings_home/Blue Bloods (2010)/Season 11/Blue Bloods (2010) - S11E01 - Triumph Over Trauma.ts
$recordings_home/Star Trek Voyager (1995)/Season 07/Star Trek Voyager (1995) - S07E01 - Unimatrix Zero.ts
