I have found no obvious routings in the environment or elsewhere (there are no sidechains active in any plugin) and I am baffled. However, even the piano roll window mentions that the region is called "side chain gate". So it seems all this is by design, albeit a design I've never come across before.
I don't see a gate anywhere in this project, nor a side chain. Who knows what this is and how this works?
* this is not my issue, but from another poster here: https://discussions.apple.com/thread/6006908?tstart=0


