Navigation menu show strange back "m-page.Page1"

Hi all, I can’t find the option to change the name of the “back” button in the navigation bar.

This is how my app looks like:

  • I start with a page called “Start”
  • on this page there are three buttons “Locations” / “Events” / “Map”
  • pressing a button opens the corresponding page.
  • as you can see, the “back” button at the top says “m-page.Page1”, but it should say “Start”.
  • strange: the “back” button show the correct name on sub-screens (like going from “Events” to “Event details”).