2018 iPad Pro battery drain problem
Just got my first iPad Pro and I'm having problems with the iPad completely draining while it's in standby. This time it hasn't been used in four days, and it was so drained I had to plug it into the charger for it to come on. This happened once before, and I thought maybe the wifi was draining it, so I put it in Airplane mode before putting it away. I stored it with the pencil attached, so maybe it's draining the iPad? I have a regular iPad Air and the battery will barely drain if it's left for days even with the wifi/bluetooth on.
Any ideas anyone? Thanks.
iPad Pro 12.9 Inch, 3rd Gen Wi-Fi, iOS 12.1