120Hz compatible iPhone 13 Pro has a bug that refresh rate is limited to 60Hz only for third party apps

The just-released iPhone 13 Pro features a new Super Retina XDR display with ProMotion and supports refresh rates up to 120Hz. However, there have been a series of reports from third-party app developers that '120Hz does not come out in the app', and Apple has admitted that this was a bug.

Third-party apps limited to 60Hz animations on iPhone 13 Pro [update] ―― 9to5Mac
https://9to5mac.com/2021/09/24/iphone-13-promotion-third-party-apps/

Apple says third-party apps will be able to take full advantage of iPhone 13 ProMotion display, software fix forthcoming --9to5Mac
https://9to5mac.com/2021/09/24/apple-promotion-software-third-party-apps/

ProMotion is a feature that achieves a refresh rate of up to 120Hz and is enabled when you switch apps or scroll the screen. This makes the screen move very smoothly, for example, when you open the Twitter app and scroll the timeline.

However, developers have reported that refresh rates are limited to a maximum of 60Hz for third-party apps. According to reports, the refresh rate is limited to 60Hz only for the 'special effects' and 'animations' of custom components, and 120Hz seems to come out in other parts. As a result, Apple-related media 9to5Mac points out that 'the refresh rate changes depending on the situation, which can be offensive to users.'

Christian Selig, the developer of Apollo, known as Reddit's client app, also reported that app users complained about refresh rates,animate (withDuration: animations:), an animation API for iOS apps. It is pointed out on Twitter thatcompletion :) does not support 120Hz.

Am I correct in seeing that UIView.animateWithDuration APIs aren't clocked at 120Hz on iPhone 13? On UIScrollView, system ones, and Metal by the looks of it, rest is still 60Hz? Pic.twitter.com/t3MeM9cj0E

— Christian Selig (@ChristianSelig) September 24, 2021

According to another developer, James Thomson, setting 'CADisableMinimumFrameDurationOnPhone' in 'Info.plist' to 'true' will prevent the refresh rate from being limited to 60Hz.

There is a workaround for the 60fps frame rate cap on iPhone 13 Pro. Set CADisableMinimumFrameDurationOnPhone to true in your Info.plist. Https://t.co/LO5Cvbr4bq pic.twitter.com/dq4RTamAil

— James Thomson (@jamesthomson) September 24, 2021

Even stranger, the iPad Pro, which has already supported a refresh rate of 120Hz since 2017, did not have a third-party app limiting the refresh rate to 60Hz.

Regarding the problem that the refresh rate is limited to 60Hz only in third party apps, it was pointed out that it is a 'specification to save battery', but Apple officially announced that it is a bug of iOS. ..

According to Apple, it is necessary to change the setting of 'Info.plist' to make the refresh rate of the application up to 120Hz, and official text on this will be released soon. In addition, a future software update will fix a bug that limits the refresh rate to 60Hz.