This is sadly true. And I’m not talking about the adaptive nature of the ProMotion display.
For all the iPhone 13 Pro/Pro Max users take that test:
Go to the Settings app, start scrolling up and down. It is smooth right? Okay now open Control Center and start screen recording (if you don’t have the screen recording button on the control center, add it for the test). Now before the countdown finishes, close control center and start the scrolling again.
You will notice that until the screen recording starts, the scrolling is “smooth”, but as soon as the countdown finishes and the screen recording starts, the scrolling is noticeably smoother!
You can experience the same thing when swiping between home screen pages, when scrolling on Instagram or Facebook, Safari etc.
For some reason, Apple is limiting the maximum refresh rate of the display to lower than 120Hz (maybe 90-100Hz) and when you recording the screen, the limit unlocks the full 120Hz!
Fun fact: Twitter seems to go up to 120Hz all the time, even without screen recording! And that’s why for months now I have noticed that Twitter app has smoother scrolling than any other app like Instagram, Facebook, YouTube etc!
So if Twitter somehow is forcing the display to go up to 120Hz, why other apps don’t do it? And why even Apple's own apps don’t?!
I’m very disappointed…
Also I don’t now if that’s the case for iPhone 14 Pro models too.
I’m running iOS 16.3
Edit: Twitter may have done that “CADisplayLink” thing you can read bellow, to go up to true 120Hz, as Apple provide instructions to developers.
https://developer.apple.com/documentation/quartzcore/optimizing_promotion_refresh_rates_for_iphone_13_pro_and_ipad_pro