Plex Documentation → Your Media
→ Naming & Organizing Your TV Show Files
→ Naming & Organizing Your Movie Files
Plex uses sXXeYY naming convention for TV show episodes. You should name your files accordingly (as shown in ChuckPa’s post above).
See Movie files not showing up in random pattern - #7 by ChuckPa and Plex / Kodi / Emby / Jellyfin Naming Schemes - FileBot for additional info.
Plex uses episode ordering from either TMDB (aired) or TVDB (aired/dvd/absolute/alternates). To choose the desired episode order, edit the show (pencil icon) → Advanced → Episode ordering.
