Android 6.0 phone call issues

[Volker]

Regarding 2):
Have a look here:

Proximity sensor (&Recalibration Tool) not working anymore with Android 6

Ok since many people here don’t seem to remember that recalibrating the proximity sensor is not all there is to it, or don’t know how to clean the glass in front of the sensor: ###Here is the official troubleshooting tool Go to > Calls > My display stays black (or on) during or after calls and go through the whole guide and follow every suggestion there.