UICollectionViewCompositionalLayout orthogonalScrollingBehavior scroll view is incorrectly positioned when using estimated item heights

I have created Feedback for a regression found in iOS 14.3. Our Apple rep suggested that I post here as well in case any UIKit engineers are looking out for issues on the dev forums.

The feedback is FB8965336 (REGRESSION: UICollectionViewCompositionalLayout orthogonalScrollingBehavior scroll view is incorrectly positioned when using estimated item heights).

The issue is caused by the use of dynamically sized cells which can have different heights based on their content. Something changed in 14.3 which causes the dynamic cell heights to be handled incorrectly when using compositional layouts in UICollectionView.

This manifests itself by moving the area on the screen that you swipe to scroll an orthogonal section to be either above or below the section.

Here is a SO post (not created by me) which describes the issue:

https://stackoverflow.com/questions/65369130/uicollectionviewcompositionallayout-bug-on-ios-14-3

I have posted a sample project in the Feedback along with a video with a side by side comparison of the behavior on 14.2 and 14.3.

Thank you.
Same issue exactly, been trying different workarounds for over a week...
Hi,

I am sorry for the issue you are experiencing. We are aware of the issue and are looking into it.

Unfortunately as of this point there is no workaround other than completely disabling self-sizing cells, which I fully understand isn't an option for most clients and we also wouldn't advice to do this.
David, our current workaround is the be more accurate with our estimates which lessens the issue but does not eliminate it. Fortunately for us, our app is not yet released so we can work around the problems that it causes and we try to just test on 14.2.
UICollectionViewCompositionalLayout orthogonalScrollingBehavior scroll view is incorrectly positioned when using estimated item heights
 
 
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