A question about n-Track on IPad and MIDI

Some IPad apps won’t work in n-Track

I have a question for those of you that use n-Track on IPads:
When I connect certain apps into n-Track using audiobus, some apps will not respond when I play them. For example: Korg Module, Sampletank, Sunrizer all won’t communicate audio into a track being recorded when I select it as the input. However when I switch from n-Track to another DAW or just the speaker connection, everything plays fine. Apps that don’t send or receive MIDI messages (like Bebot or Master FX) record into n-Track just fine. This was not happening until the most recent n-Track update. Has this happened to anybody else? Is there a way to turn off all MIDI signal communication to and from n-Track so apps won’t get confused? I’d really appreciate any help I can get from you folks. Thanks!

Let me clarify. The problems all occur when I use a MIDI keyboard attached to my IPad through an interface (the Behringer IS 202). When I switch to another DAW with everything else exactly the same, it works.