Hi Neil,I've tried turning it off, turning it on, excluding home. Turning WiFi off, not looking at the app, turning Bluetooth off my phone. Not sure what else I can try. Just had the 2019. 40.2.1 update come through now as well. Its on charge up my drive now. Going to make some notes today on miles lost from 80% charge.
I've had the same issues losing something like 27 miles a day (when idle). Last night I told the car to 'forget' wifi, I deleted the app from my phone, wife's phone & laptop so apart from LTE (internet) as far as I was concerned the car was shut off. This morning I started the car with the keycard and guess what? I still had the same miles in the tank as at 8pm last night.
You can hear if the car is asleep by listening beside the front wheel arches, just a faint whirring sound (fan or pump).