I have a very reproducible display bug appearing, both in the DPS Preflight app and in my custom Preflight app:
My first item of content in the Default Collection is an InDesign article that contains an auto-play video with a large button. When the button is tapped, the user is taken to the second item in the Default Collection, which is the Home collection. When the Home collection appears, the top "status" bar at the top of the iPad that contains the wifi icon, time, bluetooth, battery status, etc. is missing. The large DPS bar (the one that contains the back button, hamburger menu, etc) is present, but not the smaller bar that normally appears above it. This causes a blank space the height of the status bar to appear below the DPS bar and the collection content.
As soon as I go to another collection, the status bar reappears, and when I navigate back to the Home screen, the status bar is there also. As soon as I navigate back to the opening video, and return to the Home collection, the status bur disappears again.
This is on OS 9.1 and 9.2, running the DPS Preflight app and a Preflight app built with the latest App Builder code.