Ok, i found it out how it works, well it was just a little logical error:
If i send mutes via the performance channel. i.e. scene changes via CC92, i have to mute the midi channel, so it wont trigger the scene. I got a bit confused, because i need to activate the mute on the midi channel to remove the mute, as i use it to send mutes.
Sorry for your reading time, but probably it does help you when you face a similar problem. Also the scene change CC is not documented in the manual, i found it also via the forum.