no FaceTime pure audio call (audio only)

It is only possible to make or receive a Facetime video call with an iPhone 11. A pure Facetime audio call is not possible. The latest software update is installed. Same Apple ID on iPad and iPhone. **Iphone 11:** Facetime video call works, Facetime Audio only does not work (neither incoming nor outgoing) **Ipad 9:** Facetime audio and Facetime video works (incoming and outgoing) Signed in to Facetime and iMessage on both devices with the same mobile number and Apple ID. All settings were compared with the devices of another Apple ID in the same household, where everything works as desired. We do not understand why the iPhone 11 cannot accept or start Facetime audio calls. Facetime with video works incoming and outgoing, but it is not possible to turn off the camera during a Facetime video call because the button is grayed out. Here is a screenshot where it is impossible to deactivate the camera: When attempting FaceTime call, the iPhone and the iPad are ringing. When attempting a FaceTime pure audio call to the same AppleID, only the iPad is ringing.