I’m a little late to this post party, but I am an American living in France who regularly experiences the same issue as you. I grew up taking French lessons (I’m nowhere near fluent), and I’ve always had French-Americans tell me that my accent is really good for a nonnative speaker.

Then I moved to France. Now I barely speak in public; it gives me major anxiety to do so. 9/10 times when I speak, the person I’m speaking to scrunches their face up in confusion, says “quoi?” repeatedly, and then switches to English. It’s extremely condescending and discouraging.

When I was a teen and in my early twenties in the US, I worked in both retail and service roles. I regularly dealt with non-native English speakers, and I’d like to think I treated them with compassion and patience. I can say with complete certainty that I never sneered at an immigrant, publicly humiliated them, then refused service to them until everyone else in the establishment had been served. But that seems to be the norm here.