I suspect you have the same issue as me (on the car I rejected and the replacement), and occurs in 2 ways but has various symptoms once it occurs:
Failure Sequence 1
· Loud Electrical Click from the Centre Speaker
· "Error: Emergency Call. Please visit workshop error” on Instrument Cluster
· SOS Light goes off on roof
· Route guidance is not active message on Instrument Cluster
· Navigation is currently unavailable message on Instrument Cluster
· Seems to work again from next day (or hours later after leaving car), but cannot find a way to reset (like second sequence below) (So there is also no access to infotainment as it is stuck on "Loading Settings")
Failure Sequence 2
· Loud Electrical Click from the Centre Speaker
· SOS is now active message on Instrument Cluster
· SOS Light goes off on roof
· Route guidance is not active message on Instrument Cluster
· Navigation is currently unavailable message on Instrument Cluster
· SOS Light back on on roof
· To get the Navigation to work again on the Instrument Cluster you need to switch Engine off and wait a while or soft reset the infotainment by holding down the power button
These then result in other issues with the car as well as a lack of access to navigation and sometimes the whole infotainment . The car seems to reset itself to being in Europe. E.g. slowing the car to 44mph on a motorway which I believe is 70kmph and activating undertaking prevention and slowing the car when overtaking as it believes the car is now right hand drive.