RadBeacon USB failed configuration

I'm placing 3 beacons throughout my office. Two are successfully deployed but the third one is being problematic. When I attempt to configure it  with the app on my desktop's USB, it lists only about %20 of the time. When I plug it into one of my wall adapters, it never appears on the app list - ever. I've swapped the adapter with one I know is working and same things, no listing on the app. I've tried a couple of different reset method on this beacon with no change. Any suggestions from the community? Any reason to think I got a bod USB beacon? Thanks.