firebase – BigQuery shows only MESSAGE_ACCEPTED (no MESSAGE_DELIVERED) for Admin SDK–sent iOS notifications

We use the Firebase Admin Java SDK to send push notifications to iOS devices.
Messages appear in the BigQuery firebase_messaging export with message_status = MESSAGE_ACCEPTED, but never progress to MESSAGE_DELIVERED.
When sending the same notification through the Firebase Console, the BigQuery table shows both MESSAGE_ACCEPTED and MESSAGE_DELIVERED as expected.

Steps to Reproduce:

Use the Admin SDK (firebase-admin:9.3.0, Java) and the code sample below to send a notification to a valid iOS device token.

Verify the message reaches the device (the user sees the notification).

Query the BigQuery table for that message_id.

Only a single row appears with message_status = MESSAGE_ACCEPTED.

Repeat by sending the same payload from the Firebase Console. BigQuery now shows a second row with message_status = MESSAGE_DELIVERED.

Code Sample for build the message:

Message.Builder builder = Message.builder()
                .setApnsConfig(ApnsConfig.builder()
                        .setAps(Aps.builder()
                                .setBadge(badge)
                                .setSound("default")
                                .build())
                        .build())
                .setNotification(Notification.builder()
                        .setTitle(title)
                        .setBody(content)
                        .build())
                .setToken(pushToken);`

code to send to FCM

BatchResponse response =
    FirebaseMessaging.getInstance(firebaseApp).sendEach(messages);

Environment:

Firebase Admin Java SDK: 9.3.0

BigQuery export enabled

Expected Result:
BigQuery should show MESSAGE_DELIVERED once APNs confirms delivery, just as it does when messages are sent from the Firebase Console.

Actual Result:
Only MESSAGE_ACCEPTED is recorded for SDK-sent messages.

Questions for Support:

Is there any known issue with delivery receipts for iOS when sending via sendEach()? I inspected the request and see Firebase console uses different API (Firebase Campaign API) than admin SDK.

Are additional APNs headers (e.g., apns-push-type: alert) required for BigQuery to record MESSAGE_DELIVERED?

Any other things I can do to make proper deliver status work for ios devices?

Thank you