I’m having a similar issue. Custom artwork from the Poster Database shows up just fine on my iPhone and iPad (and on all Plex platforms), but not on either of my Apple TVs. What’s even weirder is that the Jurassic Park custom poster started showing correctly on the Apple TVs this week, but the other Jurassic movies still don’t show the posters correctly. The posters all come from the same collection. They don’t show in the preview on the Apple home screen, in Recently Added, in the Library, or in Playlists. All the movie details and other metadata are correct.
I’ve tried refreshing the metadata a ton (though I don’t see a way to edit metadata for the individual movies). I’ve tried with Embedded Metadata toggled on and off, it makes no difference. I tried deleting the app and reinstalling it, but it does nothing. In fact, when I reinstalled, a couple of my movies threw a file error when I tried to play them telling me to run a Plex library scan. I did that, which found the files and made them playable again, but then Infuse stopped showing the background artwork. All the other metadata remained intact.
Any help would be greatly appreciated.