Huh, after about 20 minutes of jamming it happened the other way. A4 changed and AR missed a whole round before changing. I disable a chain, then made a change, and that is when it happened. OK, weekend project is to learn how to capture and dump midi messages between these devices. My only concern is that the messages are fine, and the device responses are the issue. I’ve been programming networked applications (distributed databases) for many years, and what I am seeing, my intuition tells me, is a problem with buffers.