Why Can't I Pair My Powermeter to My Bluetooth Head Unit or App?
Updated
Try removing your powermeter from the sensor list and repairing it.
Make sure your powermeter is awake by spinning the crank several times before pairing/ zeroing.
Make sure you don’t have a dead battery. You can check the battery status on the 4iiii App.
Ensure that the powermeter is not connected to any other device or app via Bluetooth; A limitation of Bluetooth is that sensors can only be paired to one device at a time.