Weak point is still that rotates the retaining clip and the bike so / back tilt forward (depending on the focus).
The support at the transition of the stand to attract fixed with brackets for horizontal pipe does not lead to the desired success. Pipe and bracket are simply too smooth.
Now to my solution: I have a 6 cm long section cut from an old bicycle inner tube out and these inserted between pipe and bracket and pipe. Now the clip remains rock solid in the desired position.