Note 10+ from 100% to 99% Fast ?

As soon as you unplug your phone from the charger it is at 99%. 100% is fully charged so powering your phone for even a second takes power from the battery making it less than 100%.
 
The best tip I received years ago was to turn Off the battery % sign in the status bar and just enjoy what the phone brings.
I started doing this too. I'm always topping up through out the day anyway so the percentage is not even needed. In haven't had a device including the Note 10+ that can last me the whole day. I use my device a lot and have a lot of email accounts setup.