hello bro, if there is any issue then we will see battery health reaching 80% within 1 year warranty period. we can claim and get free battery replacement. If you have applecare+ or protect+ then you can claim battery replacement within 2 years period if it reached that 80% limit.
battery health refreses according to our usage and it happens when we update software sometimes.
as I mentioned in our battery health reduce video, calculate battery health from the month we purchased the device bro. 1% on an average a month is normal and some months it wont reduce.
for your usage its approximately 7 months correct? so 5% reduce is normal in this case and continue following the 20% charging rule. not draining the phone frequently helps based on my observation.
When you have heavy usage, you can charge 2 times a day. some days when not much use you will normally charge 1 time, If I am correct.