A trick you can try next time you get that issue with no need to pull fuse 19. Hit the hang-up button 5 or 6 times and the infotainment system will tell you it is going to reboot the system. It will boot into recovery and allow you to restart the system, reset it, clear caches etc.
Every now...
Just pull the radio fuse for a couple of mins. It is located in the fuse box under the hood. Sounds like the driver for the touchscreen/digitizer has crashed. If that doesn't fix the issue then you have a faulty head unit.