No "Answer" button in bluetooth phone car onboard screen

Bluetooth connection is well automatically established since OTA 8.5. Adress book is populated and to give a call works nice.
But when it is an entry call, the phone car system rings and the onboard screen menu only permits to hang up the call. There is no button to pick up the call. You have to push the answer button on the mobile phone if you want to answer. Not very useful when the phone is in your pocket.