Why won't MainStage accept incoming midi note messages from my Midi controller?

I have a 3 keyboard concert setup in MainStage running multiple instances of Omnisphere 2, Kontakt 8, and other 3rd Party software synths like Serum in Multi-Output channel strips.

Configuration is:

Keyboard 1 (88key)-Midi Channel 1/ Piano, Rhodes, Organ, Pads

Keyboard 2 (61key)-Midi Channel 2/ Comp-Synths, Lead Synths/ Aux Sounds

Keyboard 3 (25key)-Midi Channel 3/ Transition Effects/ Drops, Risers etc..

For some reason whenever I add more software instruments it will not longer accept midi notes from Keyboard 1 even though I set the Midi Input to "Keyboard 1" with everything being properly assigned in Layout View and Edit View. It will however work when assigned to Keyboards 2 or 3. This is only happening at the patch level. If I add a new instrument at the Concert level it seems to work just fine. Any ideas as to why this is happening?