Callkit loudspeaker bug / how WhatsApp fixed it?

Question

I have an app with Callkit functionality. When I press the loudspeaker button, it will flash and animate to the OFF state (sometimes the speaker is set to LOUD but

Answer 1

Referd from Abnormal behavior of speaker button on system provided call screen

The same issue has been experienced in the previous versions as well. So this is not the new issue happening on the call kit. This issue has to be resolved from iOS. We don't have any control over this.

Please go through the apple developer forum

CallKit/detect speaker set

and

[CALLKIT] audio session not activating?