Thanks for the reply. Yes, it's in the timetable but it stops only outbound there. Not really reflected on the map.

Maybe here are the limits of digitalisation. I missed the oneway character of the two lanes of Kaiserstrasse.
If you select (using the app OsmAnd) the busline 9 on the POI view you get only one blue  line which includes bus stop "Neubrunnenstrasse" which is served only northeast bound and there is no blue line shown on the southwest part of the street.