iOS Suspends My App Even There is a CallKit Call

I develop a VoIP call application. The problematic scenario is like below

  • App is in background state and the device is locked
  • App receives a VoIP Push for an incoming call
  • App reports an incomingCall to the CallKit and I start a background task for 10 seconds
  • User answers the call
  • Call is established
  • I and the background task
  • after 13 secs of incoming call received, iOS suspends my app and the call ends.

So, I would expect iOS to not suspend my app when there is an active CallKit call.

What would be wrong here, What would you suggest?

Thanks in advance for your help in advance.

Here are what background modes I use in the app

iOS Suspends My App Even There is a CallKit Call
 
 
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