mine did the same as soon as I updated 16.1.2. Coconut Battery says Im at 98.9%. IOS says 98% so it seems to be accurate for me.Prob a complete fluke, my battery health has dropped 2% on this beta on my 13pro max. At 98% now , coconut seems to confirm it so maybe iOS just better recognising it now. Battery is rubbish though , hoping another build for the proper 16.2 is released