Using XCode 15 I have added a Spotlight importer extension to my iOS app based on CSImportExtension as described here: https://developer.apple.com/documentation/corespotlight/csimportextension?language=objc
My aim is to make to text content in the app's private document format searchable via Spotlight. I implemented method updateAttributes, updated the Info.plist to include the document's UTI - that's defined as Exported Type Identifier by the app. However, searching does not work and the extension seems never to be loaded/called.
I debug the app like described here: How to debug a Spotlight extension in iOS and use iOS Settings app to reindex all items, nothing triggers the extension to be loaded.
As I have some files on the device in iCloud Drive I'd expect Spotlight to re-index them (The app does not explicitly mark them as searchable, but that should not be necessary?). When I use "Get Info" on these files in the Files app they show the correct UTI.
Any idea what could be causing the extension not to be loaded?
Thanks in advance.