An issue with a UICollectionView on the iPad

Hi. I work with a UICollectionViewController (as a primary view of UISplitViewController), compile my app on the iPad and the iPhone. The collection view behaves normally on the iPhone but on the iPad I noticed somtheing strange: 1. the selected cell has a border (strokeWidth is equal to 0 in and customView is equal to nil in UIBackgroundConfiguration); 2. Visible cells are too wide (look at the attachment)

During dragging

Any ideas how to repair? Thanks in advance.

An issue with a UICollectionView on the iPad
 
 
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