Hi janmykel,
Good day.
Are your firmware version currently on the latest WW-V16.0610.1812.58?
If yes. I would suggest you let the battery charge more than 30 minutes even the battery percentage shows 100, then remove the cable before going sleep.
Please show me 2 screenshots as below on next morning before you use the phone.
1. Battery: settings> Battery (Battery usage since full charge)
2. Battery usage: settings> Battery> please click the big battery icon :battery:
Thank you.