CCC screen iDrive - Incoming call normal behaviour ?

[studio54]

Hello,

I have the mechanical CCC screen (e82) that opens and closes.

If the screen is closed, when I get an incoming call, car speaker rings, the screen opens, and shows the incoming call with name or number, and I can anwser with knob. This is fine.

However if my screen is already opened (like listening to mp3 music), when I get an incoming call, car speakers rings, but nothing is displayed on the screen, the car speakers just ring, and I have to take my phone to accept the call, then it works, but nothing on the display, and I can't answer with the knob since there is nothing to accept the call.

Is this normal ?Any hint ?
Thank you by advance