Found an answer to the screen problem I mentioned before by playing around with the infotainment screen! When ticking the box for the screen saver option in settings, it automatically ticks the box to show the clock on screen when the screen saver is on, but if I untick the box for the clock to show and just leave the box ticked for the screen saver then the problem with the reverse assist screen staying on after reverse gear is deselected goes away and the screen changes as it should. No idea why there seems to be this connection between the clock showing and the reverse assist screen but it solves the problem I was having. Hopefully that's the last of any problems with my Scala!