I think that makes sense. English is also not my native language. It was weird - at some point I felt like I stuttered less in English, but the a few years later I feel it’s the opposite. I think it’s not related to the language, but by confidence. At the time I thought I’m stuttering less in English I had just been at a national competition (non-verbal) and was top of my class. So it could be this false confidence and the fact that at the time I just hadn’t spoken that much English to be in more situation where I stutter… So it makes sense, if you think your English is not as good you may become more stressed. Also because we use word substitutions a lot, if you don’t know enough synonyms you may have no way out. If you think that might be it - just go read some cool books in English and improve it. Either way it would be super helpful to improve your English. Mega important for any job, consuming information, communicating online.