can't open steam on iphone 11 and 12 while in a phone call.

[Dani]

Finally figured out the issue with iphone11 and iphone12 - and it is reproduced with your own demo.
You can't publish a stream while using the phone (regular call).

 

[Max]

Good day.
iOS Safari browser cannot access the microphone during a regular phone call. You can publish video only in this case:

    session.createStream({
        name: streamName,
        display: localVideo,
        cacheLocalResources: true,
        receiveVideo: false,
        receiveAudio: false,
        constraints: {
            video: true,
            audio: false
        }
        ...
    }).publish();