[CallKit] Incoming call sound alert while already in another call.

In my VoIP app that uses CallKit, while I'm in a connected call and report to the CXProvider a new incoming one only the CallKit UI is displayed (the screen with End&Accept, Decline and Hold&Accept). There's no sound indication whatsoever of the newly reported call.

Shouldn't there be a knock sound on top of the current call's audio? Am I missing some required configuration for that?

Thanks in advance.

[CallKit] Incoming call sound alert while already in another call.
 
 
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