I have the same issue and started I will say 2 months ago. My 90% charge get me 212 (used to be 214~216) and I just tried last night at 100% and I got 236 on the phone (when it was completed), but this morning on the app said 234, then when I want to the car and it reads 235.
My Model 3 have 5.900 miles and is 7 months old, my advice, don't worry at the battery degradation, 2~3% is nothing, keep in mind you will get those miles back when we get the upcoming update .
My SR+ is 5200 miles at 7 months old and behaves almost identically to yours. I charged to 100% the other day and it showed 236-237. I have also noticed when it's colder out the range shows a mile or two lower then it would if it was warm out.
I'm not worried about this as it's within margin of error of the BMS.