The first thing that comes to mind is disconnecting your battery and letting it set for 10-15 minutes and then reconnecting it and see if that may reset it.
Now I can't remember. Do you have the xt display or what display do you have?They frequently fail in Australia. Often just go completely blank. I have done about 45000km in 6 years. The dealer I spoke to said they often give trouble after 20000km. I have been more fortunate than most. The $650 replacement cluster unit does not necessarily correct all the display issues but is the most likely to fix it.
That is quite interesting, never seen em do that. I will say those are not the best displays and have replaced a couple for malfunctions.The two strokes in the first photo seem to represent rolling average speed since start and it adds bars either side depending if current speed is above or below average speed and by how much.