To recreate the mobile data matrix, you will need the device’s serial number and it’s mobile secret.
particle identify does not provide the mobile secret at this time (perhaps it’s something we can do at a later date!).
You will want to open a serial connection with the device itself and go through the steps listed in Mesh device setup without QR code? to access the mobile secret as well. Using that, along with the serial number, will provide you with the data needed to regenerate the data matrix.
If you are continuing to have difficulties with this, do feel free to reach out to support, providing your device ID or serial number and we can assist on our end.