Tested on iOS 18.5, Beta 1 (22EF5042g), same issue is still present. getFileProviderServicesForItem fails when called from the consuming app with: Error Domain=NSCocoaErrorDomain Code=513 "The file couldn’t be saved because you don’t have permission." The supportedServiceSources method in the service hosted by the provider app is never invoked when this occurs.

Updated sysdiagnose has been uploaded to feedback report https://feedbackassistant.apple.com/feedback/16933592