The old Teslas originally used a fixed buffer of 4 kWh. Now I believe they use a value that can vary with total battery capacity. I think it is now 4.5 % of nominal full pack. That would be about 4.36 kWh for your 96.9 kWh battery. What is your CANBUS buffer reading?
I know this is not related to your issue, but I just wonder if they are still doing that with the new cars.
Your car shows 347 miles with 100% charge with 19" wheels. I think that wheel size is a selected value in your car. If you change it to 21", does it change the rated miles to a lower value?
Changing to 21" wheels shows 320 miles at 100% so the EPA constant appears to only be incorrect for the 19" wheel config.