This day's TIL, thanks!
I knew that "or so" is also a common expression in the English language, so assumed it to be used in the same way as in German.
As I just learned, this is only the case when dealing with numeric values (e.g. "five eggs or so" and not with uncertainties regarding more general things or distinctions between things.
So "Looks like a bug or so" apparently would be wrong.
As I now understand it you would say "Looks like a bug or something" instead?