Voip pushes not launching app if terminated in iOS 13

There's been a longstanding issues with Voip pushes not being delivered to the app if the app has been terminated and the device rebooted PushKit notification not arriving after application kill AND device reboot

However with iOS 13 I'm seeing that they are not being delivered if the app is terminated without the phone being rebooted (currently observing this on 13.1.3).

This is 100% reproducible, but the number of pushes that get delivered to the app after its terminated appears for the first time appears to be variable. Often the app will continue to receive pushes after being terminated but only a few before it stops receiving them entirely. However on some occasions it doesn't receive any whatsoever after being terminated. If the app is launched again then its starts receiving them again BUT only if the app is in the foreground - move it to the background and it doesn't receive any.

Do your messages have the time to live property set? Like facetime voip calls for example, the push would need to be delivered immediately. Wondering if the system is queuing up the messages for a later time or not. I assume any VOIP push would require immediate delivery (or phone offline) for calling purposes, just a thought to double check.

I'm facing the same issue in iOS 15.1 Push Kit notification not arriving when app is killed or in background. But it's working in iOS 14 which is strange. Did anyone facing this issue in iOS 15.1?

Voip pushes not launching app if terminated in iOS 13
 
 
Q