[Zubersoft]

In the file you provided, the second chord was written as [B ] with a space after it. This causes it not to be recognized as a valid chord. Was that intentional? If I remove the space, then regardless of whatever source localization I select it, it's still highlighted correctly. I can't reproduce what you displayed above where only three out of the four chords is recognized. 

Regardless, just so I understand exactly what the issue is as you've reported:

1) If source localization is set to German, and display localization is set to "Default", H is not changed to B and B is not changed to Bb because isn't transforming chords unless they are transposed
2) If source localization is set to German and display localization is set to "Default", then you also encounter issues with transposing where the second chord is transposing identically to H instead of being treated as Bb.

Is there anything else I'm missing?

Thanks,
Mike.