Sync 3 screen blanked out

[NortonSS]

Out for a spin yesterday using apple car play and apple maps , in an area of poor or no signal (I think) the screen blanked out. After about one to two minutes the screen re-booted (Ford logo) and then went back to apple maps as though nothing had happened. Is this normal ?, in the past driving through the Forest Of Dean using apple maps and entering areas of low signal the map just fades out but the screen does not turn off.