[PhilipW]

Kodi doesn't handle movie sets very we'll at the moment, you'll need the addon, can't remember off the top of my head what it's called though.
Kodi without the addon just uses the first movies artwork I think

I found some info on anadd on called moviesets, loaded it from a zip, but it only seemed to make things worse. Couldn't find much in the way of information on it. So I ended up disabling it.