firebase cloud messaging – Kotlin Multiplatform iOS — FirebaseBridge (Objective-C) not called from iosMain (FirebasePushNotifierImpl.init not running)

I have a KMP module using a native bridge in Objective-C/Swift for FCM. Android works fine, but on iOS the FirebaseBridge methods are not called from iosMain. It seems FirebasePushNotifierImpl either doesn’t initialize properly, or FirebaseBridge.initializeFirebase() never runs.

git:

Relevant files:

1) Kotlin (iosMain) — FirebasePushNotifierImpl.kt

internal class FirebasePushNotifierImpl : PushNotifier {

    private val scope =
        CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate)

    init {
        scope.launch {
            FirebaseBridge.initializeFirebase() // expected to call iOS code
        }
    }

    // getToken, deleteToken, subscribe, etc.
}

2) cinterop .def

language = Objective-C
package = firebasebridge
headers = FirebaseBridgeObjC.h
compilerOpts = -I${projectDir}/../../iosApp/iosApp

3) Swift implementation

@objc public class FirebaseBridge: NSObject {

    @objc public static func initializeFirebase() {
        DispatchQueue.main.async {
            if FirebaseApp.app() == nil {
                FirebaseApp.configure()
            }
            UNUserNotificationCenter.current().delegate =
                UIApplication.shared.delegate as? UNUserNotificationCenterDelegate
            UIApplication.shared.registerForRemoteNotifications()
        }
    }
    
    // getToken, deleteToken, subscribe, unsubscribe...
}

4) Objective-C header

@interface FirebaseBridge : NSObject
+ (void)initializeFirebase;
+ (void)getToken:(FBTokenCallback)completion;
+ (void)deleteToken:(FBVoidCallback)completion;
+ (void)subscribeToTopic:(NSString*)topic;
+ (void)unsubscribeFromTopic:(NSString*)topic;
@end

Expected behavior:
FirebasePushNotifierImpl initializes and FirebaseBridge.initializeFirebase() executes (I should see NSLog output, and FCM registers device token).

Actual behavior:
No logs from FirebaseBridge, device token not registered. Looks like Kotlin → Objective-C bridge is not called. Build succeeds, no compile errors.