User doesnt get PWA Notifications on iOS using FCM after a couple attempts

Question

I'm using Firebase Cloud Messaging to send Daily notifications to iOS users who have a PWA app installed. I've found that for a given token, I can only successfully send 2 notifications. Beyond that the call will return a success (verified in the logs) but the user never gets the notification. Havent tested it on android yet to confirm if this is an iOS specific issue.

        const message = {
          notification: {
            title: "Practice Reminder",
            body: "Time for your daily fretboard practice!",
          },
          token: data.token,
        };
        getMessaging().send(message)
        .then((response) => {
          // Response is a message ID string.
          console.log('Successfully sent message:', response);
        })
        .catch((error) => {
          console.log('Error sending message:', error);
        });

Answer 1

As of the 2nd of June, the solution suggested here fixes the problem. i.e.: replace the onBackgroundMessage with

self.addEventListener('push', function(event) {
    console.log('[Service Worker] Push Received.');
    const payload = event.data.json();  // Assuming the payload is sent as JSON
    const notificationTitle = payload.notification.title;
    const notificationOptions = {
        body: payload.notification.body,
        icon: payload.notification.icon,
        image: payload.notification.image,
        badge: payload.notification.badge,
    };
    event.waitUntil(
        self.registration.showNotification(notificationTitle, notificationOptions)
    );
});