iPhone display dims when warm after cold

Ive been having an issue with my iphone display and its really weird.Whenever im sitting in a cold atmosphere like an AC room the dislay appears normal.But the moment you start using the phone or the moment it gets hot the display turns dark

dark as in i can see whats happening in the screen but still the display is really dim compared to other iphones

is this just me

ive been to a service center and they straight up recommended a display change

does anybody else hae the same issue