Device status message shows conflicting battery level & external power source

On a device status message I am seeing batteryLevel of 0, which from docs indicates 0 means external power source. But the external power source field is false. The end device is externally powered, so it seems just the externalPowerSource field is incorrect while the batteryLevel is correct.

    "externalPowerSource": false,
    "batteryLevel": 0,
    "batteryLevelUnavailable": true
 }

Anything I could check in the config to see if I have something set wrong that would result in this output?