After doing some searching on an XMLTV EPG, I found this reply by an admin on www.iptv-epg.com, a vendor for EPG XMLs… seems that Plex is an island with Gracenote on this…
Anyone have a solution?? Oh, and it can’t be a Windows-only solution, as I’m 100% Mac)
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(from iptv-epg.com):
09-05-2018, 09:19 AM (This post was last modified: 09-05-2018, 09:24 AM by Epg Admin.)
This was already discussed a few times in this very forum, but here we go again for those, who are lazy to search 
It is impossible.
Plex uses its own EPG which they receive from Gracenote.
Gracenote has a self developed category system which nobody knows and nobody else uses.
Plex uses that system to categorize shows and it’s tied to the episode system of shows which is an absolutely wrong approach.
Everything that can not be categorized in Plex, will be categorized as movies.
You have to talk to the Plex developers and ask for “onscreen” or “xmltv_ns” episode system, which is the standard everywhere in the world, except at Gracenote, and a separate category system with humanly readable names made up of letters instead of some obscure numbers.
Actually ask them to respect the XMLTV standards and you will be fine.
