Public transport in Maps has been broken for almost a year now in Germany. Bing in the browser, ok, but the maps app on Desktop or Mobile just puts out crap information.
Wanna try?
Navigate from
Hackescher Markt, 10178 Berlin
to
Bundesplatz, 10715 Berlin
Maps will tell you to use the same S-Bahn twice. Bing Browser will tell you to use S, then U9 (subway).