KODI, VDR and H.265 (5.1 Audio) and VNSI Plugin

I have the following setup: A small PC with VDR 2.3.8 as the server. As the client I tested a Vero4K and Linux Clients. On both clients with KODI 17.x (I tried several versions) there are dropouts in Sound when the Sound is 5.1. (Stereo sound works without problems).
This behaviour is found when playing Live TV or recordings from Live TV.
When I play the same over vlc, the sound is ok. So I think it's a problem with the plugin.
Has anyone experiences with this setup?

Thanks

Holger