upnp tvshows – watched status does not work

I have a upnp kodi server (16.1) on windows 10.

On my clients wih Kodi 16.1 I can access all the movies and tvshows. With movies everything is fine. With tvshows there are 2 problems:

1. The watched status does not work. Kodi doesnt remember how much I already watched of an episode. I first have to close the client and start it again and then these information are updated.

2. If there is a tvshow with only 1 season I get no cover for this season. The same for specials.

Is this a bug? Should I try Kodi 17?