If you have a Gen 3 charger it communicates with the car. I had both Gen 2 and 3. The Gen 2 it would charge to 80% and stay. The Gen 3 allows the car to run down a bit before bringing it back up to 80% possibly to allow the BMC's to balance the batteries. What you describe is common with gen 3 charger.I updated to 2021.24.3 a couple days ago, so I don't know if that affects things, but I plugged in my MY last night. When I came out this morning the display read "fully charged" and the battery was at 79% despite the charging limit being set to 80% on the phone. I'll see what it does next time.