iPhone 13 Pro Battery Maximum Capacity Not Changing

I've had this iPhone 13 Pro since December of 2022. It initially showed a maximum capacity of 84% in the battery health & charging setting. Since then I've charged the iPhone every night and sometimes during the day. I've noticed the battery is much worse than it was back in 2022. But the maximum capacity still has not changed, it still shows 84% which can't actually be the case. I have apple care so once the battery health drops below 80% I qualify for the free battery replacement. Is there a way to somehow get the iPhone to show the real maximum capacity?