Unable to answer "Are these opening hours still correct?" – on floor 1: Dr. Karl Hellemann (Primary Care Physician) – https://osm.org/node/2469976384 via StreetComplete 58.0:

Ordination
Dr. Lilian Masoud-Landgraf

und 

Ordinationsgemeinschaft

Attached photo(s):
https://westnordost.de/p/217381.jpg