TV Show matching Red Dwarf

I just tested with this structure (the library points to test_tv) and it worked as expected:

test_tv/
└── Red Dwarf (1988)
    └── Season 01
        └── Red Dwarf (1998) - S01E02 - Future Echoes.mkv

You’re not just swapping back and forth between the legacy scanners/agents and the Plex TV Series/Plex Series scanner/agent, are you? Nothing good will come of that. Stick with the new scanner and agent, it will (can, obviously) work.

Can you show a screenshot of this page of your library configuration?

Finally, switch back to the current scanner/agent (if not already) and perform the Plex dance on the Red Dward series. Then, collect your server logs and upload them here.