I'm having problem with my VoIP application. My app uses Callkit and VoIP push notification to make SIP calls between same app. Sometimes after taking the phone the call doesn't start. I found out iOS is not sending back audioSession didActive response to my app. Is this known issue or bug?

I had strange experience few days ago. After sending VoIP push notification request properly to APNs it took nearly 10 minutes to actually receive the Push notification. Could this be cause by other than network issues? (i.e. APNs issue or iOS issue)

Callkit returns error code=106. I can't find what this error code means in official documents. What is this error code? Has anybody seen this error code so far? My app is VoIP app using APNs VoIP push. Below is log example of my app. 2026/04/26 09:01:45.752 [436:103]CallManager incomingCall(::::_:completion:):228: error Error Domain=com.apple.CallKit.error.incomingcall Code=106 "(null)"