I'll have to check later, but there might be a way inside the engineering menu of the IVI system. In my other car (a 2022 DS4) I can access that menu by holding down three fingers simultaneously for a few seconds until you get to enter a passcode. In my case its 1232020, but I'm not sure that code applies for the 308/408. There might be a button somewhere in there to reboot the system. Be careful around there because you might mess up things!