I have experienced completely the same thing several times. It dos not always helps to turn the system off and on again, the only thing I have found that helps is to turn off the system (the whole car), remove the SD card, turn on the engine and when the sign "you do not have navigation, insert the navigation SD card is in ..."shows up , put the SD card back in and then it normally comes to live again (the radio is always playing?). There can be 1-3 weeks between the system breaks down, which is frustrating when you meet up at the workshop and trying to explain the mistake ... and they send you a pathetic smile... because everything is working fine.. Doeeh
I've now filmed system several times where it does not start up for documentation.
For your information, I can tell that my Infotainment system is updated to the newest version.
Mazda CX-3 150 AWD Automatic Optimum 2016 -
Honda Civic Sport 1.8 Automatic 2012 -