Midi routing error or what?

Hello, i have an issue with recently bought Moog Slim Phatty. I need to use it with Mainstage but the problem is that when i connect a midi-out strip (at midi channel #5 for example) to my patch and set the same midi channel for midi-in port at my Moog SP it starts playing at all midi channels i send from my midi-keyboard. So, i set up channel #5 on my midi keyboard, add midi-out strip at Mainstage with midi-out channel #5 and set my SP midi-in channel #5 - and got a Moog SP, playing at all midi channels i send from my midi-keyboard, not only 5, but 1,2,3...16. What is my error, what am i doing wrong? Or it is hardware\software error?