Can't handle multiple calls
What is the actual behaviour?
I'm on a phone call, and another call comes in.
The ringtone starts playing very loudly, which is massively distracting. If the first phone call is still connected, then they will also be getting a ridiculously loud ringtone being shouted down the line at them.
I am then presented with 2 buttons, one of which is the blue button to answer the call. I have no idea how to actually reject the phone call, as there is no red button. Panicking, I click the left button with no idea what it does.
The incoming call disappears for a second, then it starts ringing again as if the call is coming in again (but, I highly doubt this person tried to ring me twice in 10 seconds). This time I accept the call in order to stop it.
The first call has long since disappeared, I have no idea if they got a deafening ringtone and me shouting at my phone in confusion, or if they got disconnected the moment the other call came in.
What is the expected behaviour?
Anything better than that.
There is an issue relating to visual design at #59.
That might solve half the issue.
But, most urgently, the incoming call needs to not deafen everyone involved (e.g. a gently beeping sound from the top speaker) and it needs to be obvious how to reject a call.
I think implementing the UI in #59 is of less importance than just getting the most basic flow working.