Screen randomly scrolls while navigating

Hi
I mainly use my 5x for navigating on hill walks which works really well on my pre-prepared routes. One thing that drives me insane is that, it seems to change from the map screen to the main data screen completely at random. Sometimes it will only stay on the map 30 seconds, sometimes for half an hour, or any other duration depending on what it feels like. Auto scroll is turned off.
It wouldn’t be so bad if I could move the map screen to 2[SUP]nd[/SUP] in-line but can’t seem to bae able to move it as when adjusting the data screens, the map doesn’t appear so I can’t re-order it.
Any ideas?
Thanks