If the Factbird DUO firmware update appears to be stuck, it may be because the device temporarily lost its connection and is trying to reconnect. In most cases, the update will continue on its own, so please be patient.
If the device remains stuck, contact support. Make sure to provide the hardware ID and let support know the color of the status LED.
If the update is stuck at 0%, it could mean the device was offline when you started the update. Updates can be initiated even if the DUO is offline — in that case, the update will automatically begin once the device comes back online.