FileProviderExtension workingSet enumerator didn't call

Hello!
I have a problem with working set enumerator (Recents tab) in Files app. I implement a working enumerator for Folders, it runs enumerateItems(for observer method when I move to the folder in UI and everything works fine.

And I have a different enumerator for working set too, but it is not created and enumerated anything.

override func enumerator(for containerItemIdentifier: NSFileProviderItemIdentifier) throws -> NSFileProviderEnumerator {
        let maybeEnumerator: NSFileProviderEnumerator?
        if (containerItemIdentifier == NSFileProviderItemIdentifier.rootContainer) {
            let directory = repository.directory(for: containerItemIdentifier)!
            maybeEnumerator = FileProviderFolderEnumerator()
        } else if (containerItemIdentifier == NSFileProviderItemIdentifier.workingSet) {
            maybeEnumerator = FileProviderWorkingSetEnumerator() // not called
        } else {
            _ = repository.item(for: containerItemIdentifier)
            if repository.isDirectory(at: containerItemIdentifier) {
                let directory = repository.directory(for: containerItemIdentifier)!
                maybeEnumerator = FileProviderFolderEnumerator() // works fine
            } else {
                maybeEnumerator = FileProviderItemEnumerator()
            }
        }
        guard let enumerator = maybeEnumerator else {
            throw NSError(domain: NSCocoaErrorDomain, code: NSFeatureUnsupportedError, userInfo:[:])
        }
        return enumerator
    }

I'm trying to call working set enumerator in startProvidingItem method using signal, but it doesn't work.

override func startProvidingItem(at url: URL, completionHandler: @escaping ((_ error: Error?) -> Void)) {
        loadItem {
            //when done with loading
            NSFileProviderManager.default.signalEnumerator(
                for: NSFileProviderItemIdentifier.workingSet,
                completionHandler: { error in
                    if let err = error { print(err) }
            }
        }
    }

Does FileProviderWorkingSetEnumerator initialize automatically when I open Recents tab in Files app? Should I call it somehow directly from FileExtension?
Thank you!