@thomaso It must be a bug, you see it in the video in my first post. Really weird behavior. The leading jumping and gaps make no sense, because there is enough space for the given text, but it is overflowing to the next page.
The "last screenshot" you are referring to: Here again, there is much more text overflowing to the next page. The screenshot before showing the first step. It makes no sense that, when i make more space available less text is shown and stretch out much more.
I added a screenshot out of InDesign wich does the job perfectly fine.
Sorry, for my probably bad english, I hope you could understand.