UIDocumentPickerViewController: Cannot access file from OneDrive

Question

I am struggling with accessing files from the Location OneDrive through UIDocumentViewController.

The error says:

Error Domain=NSCocoaErrorDomain Code=260 "Die Datei „Testfile.txt“ konnte nicht geöffnet werden, da sie nicht existiert." 
UserInfo={NSFilePath=/private/var/mobile/Containers/Shared/AppGroup/11E04153-649E-416F-9860-2EA9C0913A18/File Provider Storage/item|1|18a17c69%2D5d6d%2D4b16%2Db388%2D4a9834e9440b/Testfile.txt, NSUnderlyingError=0x281202310 
{Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}

The Controller is initialised the following way:

let ctrl = UIDocumentPickerViewController(forOpeningContentTypes: [.image, .audio, .video, .item, .content])

And in the delegate method I do the following:

        func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
            
            guard let documentUrl = urls.first else { return }
            guard documentUrl.startAccessingSecurityScopedResource() else {
                parent.errorText = "Developer Error: Can't access security scoped resource."
                return
            }
            defer {
                documentUrl.stopAccessingSecurityScopedResource()
            }
            do {
                let data = try Data(contentsOf: documentUrl)
            } catch {
                parent.errorText = error.localizedDescription
            }
        }

Any help is appreciated!