Severe hangs with iOS 17 Beta 2 when using iCloud

I have my app including iCloud support in the App Store for many years now. When I run the app on iOS 17 Beta 2 I am experiencing a very bad performance because the main thread seems to be blocked most of the time.

When I run the app using the Time Profiler in Instruments it also reports the hangs and the busy main thread.

I looked into the profiler window to see methods with long runtime. The most prominent method was: [BRQuery itemCollectionGathererDidReceiveUpdates:deleteItemsWithIDs:] coming from "CloudDocs". That seems to be some iOS internal class.

I do not really know where to look next and I want to know whether somebody of you also experienced a similar problem?

Thanks, Dirk