Thank you very much for the sample GraphML file.
When I run "Layout" -> "Flowchart" with default settings except "Positive Branch Feature" set to "Ja" and "Negative Branch Feature" set to "Nein", I get the expected result:
Corresponding GraphML.
The lower "Team auf Platz 6-25?" does not look great, because the algorithm prioritizes "less crossings" over "one Nein edge connects to the left side of the node and one to right side".
What settings other than text for positive and negative branches did you change to get your result?