I did some tinkering with this yesterday. This was happening on two different 10ND dimmers. I reset them using the 3-3 button taps, and then went to re-activate them in the system. When attempting to reactivate, I found that my main repeater was in safe mode (indicated by the software, and then I went and physically looked at it, and it was flashing red lights).
I pulled power to the main repeater, waited a few minutes, restored power, and everything seemed OK (it was no longer in Safe Mode). I then re-activated the problematic dimmers, and they started working again...status now shows correctly...
I'm guessing that if the problem were with the switch communicating with the Main Repeater, it wouldn't re-activate in the system, because it wouldn't be able to communicate.