Delayed Push Notifications only on iPhones.

Why are push notifications to iPhones being delayed by 3-5 minutes after they are sent out? How can this be fixed?
The whole thing does work if iPhone users don’t get the notifications at the same time as Android users!
The rest, please correct me if I'm wrong. But as far as Im aware, you don't get Push Notification to deliver on Android and iOS on the same time. Example, my app is relying on Firebase to push out the Push Notification once sent out via Portal. I have always receive notification first on iOS, following about 20 - 40 seconds later on Android.

It all depends on the service provider you are using. Like my case Firebase, I have no control over the time.
Delayed Push Notifications only on iPhones.
 
 
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