Interesting. I read somewhere that it depends on, how you talk to Alexa - and that seems correct:
If I say
"Alexa, fahre Rolladen Büro oben hoch/runter"
then it works correctly with the up/down order and with the 20 percent.
If I just say
"Alexa, Rolladen Büro oben hoch/runter"
then it mixes up the order and uses 10 percent. Is this expected behavior? If so, from whom? Alexa itself or the binding :)? Is there any configuration to adjust this somehow (to support leaving “fahre” out)?