I saw once an attempt from Mike to deal with phantom Zigbee devices. His idea was:
- Join a new Zigbee device successfully
- Factory reset the device without removing it from Hubitat
- Change the DNI in the device to the one that is not listed, it is 6DC3 for you
- Change it to the “Device” Driver
- Go into the device and hit the “Get info” button
- Now remove that device from Hubitat
He said it theoretically should work, admitting that he had never tried it