I'm an expat (immigrant?) in Germany. IME expat circles are a problem in itself. People who cling to them end up leaving much quicker than people who mingle with natives, or mingle with people from other nationalities. Not only you don't make long-term friends in those circles (because people are constantly leaving the country), but there's a lot of negativity and shit talking. You need to at least make an attempt to adapt, and those circles can be a replacement to that.