Battery health dropped too fast
I bought my iPhone 14 pro max deep purple 256 Gb recently on December 4th, 2022. It’s been only 3 months till today and my battery health dropped from 100% to 99% even though I have been following the ways to preserve battery health (charge between 20 to 80 percent, use dark mode, etc). I was told that for the next 6 months, it would definitely stay 100 percent even if we are having fair usage, even my screen time is less, my screen time shows that I hardly use 6 hrs in an entire week (which is true since I hardly get time to use the device)
What do I do? Any help?
iPhone 14 Pro Max, 16