> It's definitely not open hostility, but many little things which quickly give you the impression that you are not welcome and seen as a threat.

Literally what most expats go through in Europe. I live abroad for 6 years and here, a Central EU country, this also happens. I am trying to learn the language and even then I got told implicitly several times that I will still be treated as a foreigner, no matter how much culture and language I learn from the local country.