Are specials requestable in jellyseerr? They aren't in overseerr, so they have to be manually requested in sonarr. Also, sonarr uses tvdb and as I understand it, it's unlikely to ever support tmdb, so if jellyseerr uses tmdb like overseerr does, then that could be another source of confusion if there are differences.
For now if you use sonarr you just have to accept tvdb and set other things to use tvdb where possible (Plex and jellyfin), and accept mismatches where it can't be changed (like overseerr / possibly jellyseerr too since it's a fork)
I was curious and tried that on my Samsung TV from 2016, it loads a grey background and does nothing