Xiaomi Aquara Door Sensor - Battery Showing -415%

Hi - I’ve recently installed a new Xiaomi Aquara Door Sensor. Added the Device Handler… all paired up and working. I used the bspranger device handler from here

The only problem is that from when these went live - I’m showing that the battery is at -415%

Being an absolute newbie to this - what do I need to do in order to try and correct this?