Hi Robert,
As you can guess, that means the logic informing about MIDI input change is not the same as for Audio Input, inside Cakewalk.
The API is exactly the same. Even more, surface plug-in (AZ Controller) has no consistent way to detect "Instrument" tracks.
Instrument tracks exposition throw Surface API is traditionally buggy, apart from omission of one half of parameters. Technically and logically
an Instrument track consist of 2 completely separate tracks, with all corresponding parameters. Cakewalk only visually represent them as one. In API
they also represent them as "one", so taking some parameters from the first and some from the second, without a possibility to choose which parameter
we really want. Summing that with some bugs (I don't remember when was solved and which not), the result was always disappointing.
Do you have MIDI part in your mixer?
Regards,
Alexey.