I’m not sure about European English, but at least in American, it’s not normal to say “I live in Germany since a bit”. If you don’t live there anymore, you could say “I lived in Germany for a bit”. If you still live there, you could say “I have lived in Germany for a bit”

Based on some (limited) experience with people for whom German is L1 who are speaking English I suspect (without knowing any German myself) that this is a typical formation that a native German speaker would use when intending to form a "for a bit" phrase in English. tl;dr, I think it was a joke.