Garage battery level is null%

Using a low battery notification smart app I recently started getting this notification, any ideas what null% is?

Null means when the device reported the battery level the event was corrupted or malformed and the platform couldn’t get the correct battery level and replaced it with empty (null). This happens from time to time depending on the quality of the mesh. It’ll fix itself when the device reports the next battery level update (typically within 6 to 72 hours). If it doesn’t then the device is having issues with the mesh.

If you’re using the Customizable Low Battery notification app, update to the latest version where it handles the null notification in a more graceful manner.

I upgraded to the newest version and the notification now says garage battery unknown, looking at the device it says battery ok, so I don’t think the device is meant to display the percentage.