Another sat nav issue

Hi all, can anybody help please? I have a 2016 q30. My sat nav system keeps freezing. the problem also affects the volume control. For example, at times the volume will only control the traffic announcement. I can still access the relevant control within the settings page and it will work, just not with the volume knob. Once I have turned the car off then on again, I have full functionality again.
has anyone else experienced this?

many thanks

Wayne