I had an issue where one of my zwave modules was no longer responding to commands and was not communicating. After reviewing the logs and attempting a few zwave repairs I noted a ghost zwave ID showing up as failed in the repair attempts as well as my zwave module within the hub crashing and needing to be reset frequently.
I opened a support ticket and they were able to remove the ghost device which resolved the crashing issue. They also recommended re-adding the device that was not communicating. I executed a zwave exclude first which did work, but I noticed when it removed the ID was 00 instead of the expected 21. For some reason, the module must have lost its network ID (clearly not SmartThings fault). I manually deleted the device with ID 21 from SmartThings I was able to re-add without issue.
Support was prompt and I had a positive experience. I just wanted to thank them and share my experience with the rest of the community.