Another reason we assume this is a system-level SwiftUI bug affecting German is this screenshot from another colleague, showing an iMessage. When copying the message, the text is complete in the clipboard: "Der Schulleiter Raum für Lehrkräfte. Eine Knallerschule!"

Hi, I’m a colleague of Kai’s. I think the missing piece here is the app language. When I run Kai’s code snippet, I only see truncated text when the app language is set to German (via the scheme’s run options), not when it is set to English. Here are screenshots from the iPhone 16 simulator (Xcode 26.5b3, iOS 26.5).

This issue is still present in tvOS 26.0b1.

This was fixed in iOS 18 beta4.

Thank you for confirming the bug. The feedback ID is FB13942310

There is now an API available in iOS 17: https://developer.apple.com/documentation/uikit/nscollectionlayoutdimension/4173072-uniformacrosssiblings

the issues where resolved with Xcode 13.3.1

The issue is fixed in iOS 15.2 RC