Rebecca Goodall first moved to Britain when she was 10, and lived in the country on and off before settling here permanently in 2010. She teaches real estate at a university about two hours north of London, has a child who was born and raised here, and speaks unaccented English—she has, she told me in frustration, a “bloody master’s degree.”But until recently, Goodall didn’t know if she could still live here.As a German citizen, Goodall is among the millions of European Union nationals living in the U.K. whose immigration status was thrown into doubt after the 2016 Brexit referendum.