The FIS of S-Bahn Köln BR 423 is just a joke. Line number is missing and the font is false. The S19 doesn't even terminate in Cologne.
The automaticly FIS is not a good thing imo. The line number do not show, it looks a bit wrong, the text is bit odd. I hope they'll fix that soon...
The reason for this is very simple they decided to Reskin Hauptstrecke München-Augsburg 423 to S-Bahn Köln that's how it got the wrong font in the first place. Correct sign is S19 Blankenberg also affects S12 too to which Au(Sieg) final destination.