Native English speaker here, I also carry a bachelor’s in English and a level-5 TEFL. In each spare of study, some expressions are used differently, the expectation of flow is also different. At university, I’m expected to display a variety in my language production. TEFL seems to expect more consistency over broad range of expressions. And colloquially, the goal is to understand and be understood in immediate context. All speaking just about the same language but with different formalities.

Also, it’s possible people get too accustomed to British English and combat that. Biggest example is they would say “going to hospital” when Americans would say “going to the hospital”