I have switched from XBMC to ATV4K and Infuse7 and I noticed that TV-Series under “Unwatched” are not grouped - see “Dexter” or “Girlfriend Experience”:
the grouping in “All Series” works (sorry, new user, otherwise I would add more images)
All series are in separate folders, seasons are separated and this works perfectly fine for Kodi and Plex (meh, new user - can not add another screenshot)
I went as far as renmaing the Seasons (from previously “Season 01” to “Season 1”) as I thought the leading “0” would cause a problem.
Also, how would I add “Unwatched TV Series” / “Unwatched Movies” as a favorite to the home-screen?