Germany's 'freedom of speech' is just qualitatively different and much less meaningful. It's illegal to burn the German flag, use a diminutive to address a police officer (du vs sie). More troubling it's illegal to insult a foreign leader (and the government must determine whether criticism is 'abusive', which would constitute a crime)
https://en.wikipedia.org/wiki/B%C3%B6hmermann_affair
Chanting 'from the river to the sea' is illegal. Publishing statistics that suggest that refugees commit crimes at a higher rate. Calling a politician a 'criminal'. And of course the nazi stuff you mention. In general, 'human dignity' is considered more important that free speech.
I agree, the detention is insane, unnecessary, arbitrary, and a complete abuse.