that's normal for all iphones

I had an X and also 7, etc etc. I feel the reboot speed is almost the same. Maybe 11 have more things to load. Haha

Mine still 100% since 27/9. Just normal charging overnight everyday.

98% now in less than 2 months using. normal charging habit. no phone talk or use during charging. 1 or 2 days one charge. unplug once 100% never overnight charging.
previous xs max 99% health after 11 months used.

I read some article about ....

some say, it the OS issue where it is generally not true and apple had put there to mislead us....

some say, it will drop to certain percentage and it will stop drop until year later because the each battery capacity is different as some hold high charges and last longer then others...
while other says, if you happen to notice a big drop during few month, better go and have apple center run diagnostic on your battery.

Do let us know on the result after you have them check....i seem mine drop 1% too but not that significant only about 1 month plus after own them ....charge 1 1/2 days once

since Sept 20?

pls let us know what is the result. i might do the same too in coming months.
i think this 11 pro max maybe having similar battery drop issue as last time Xs

Mine is also at 100% battery health bought on launch day 27/9 as well, usually I charge my phone every 2 days, damn this new iPhone 11 Pro Max battery really last longer.

I don't advise you putting your phone on flight mode while charging, unless you have a second phone for people to contact you on emergency matters.

P/S: Add on...

some say it is the heat factor from charging or environment factor causing damage (Like forumer here mention)

some say using 18w charge speed up the degradation of the battery and used 5w will slow down the percentage drop....

Some say charge from 20-80% will help to prolong the battery life.....

For once, we never know until we take it to diagnose the battery....somehow i feel apple battery been very fragile 

was talking about your case with a friend.
he said check your charge port. you might have dirt etc
and from there it degraded your bat.
no sure how reliable this is but just check

You mean the paint job near the camera lens looked like it peeled off? Got a pic? It was a common problem on the iPhone 7 / 7 Plus back in the day.

can take a photo on the camera ring part?

Before upgrading, there is a message of Service Battery.  After upgrade to 14.5 and the Service Battery still appear, then you may go to AASP to replace the battery FOC.

Send to Apple is better.
What is your current battery health?

Mine is 88% on a 2 years old phone.