I had the same issue. I was not used to unfamiliar poeple around me. It’s weird. Because i was a sports trainer/teacher for 4 years. And i was that confident that my stutter was not bad at all when i was teaching or leading. Now i’m 2 years in Software engineering (big change i know) and my speaking is way worse. I think it mainly come because i’m not used to speak with people that often.