iPhone 14 Pro Max display brightness

[tmh1973]

Could someone please explain this? I have an iPhone 14 Pro Max (256 GB) and when I compare its display to other iPhone 14 Pro Max units at the store (128 GB models), the screen is dimmer than the store models at similar brightness levels (and also dimmer even with brightness turned up to the max) and with identical settings (true tone and auto brightness on, reduce white point off). Only with auto brightness and true tone off, does the display show similar brightness to the units in the store. Is my display faulty? Am i not getting the 2000 nits max brightness? Many thanks in advance for your response.