"Fix" I have a 2016 MacBook Pro with 358 cycles mine did the same after update- Here is a Fix that has so far worked Reboot hold Option Command P and R wait for the second chime and you should be good to go

Big Sur Battery Service Reccomended Fix This is a bug, I have fixed it 3 times with the SMC and PRAM reset- Ill post how to do it on my YT channel at my name in the bio.