Yes when I started speaking english, I had to talk much slower than my first language so I stuttered less, but right now Im more fluent so I stutter same amount I stutter in my first language lol. Another reason for me would be, that I know what words and sounds I would stutter on and I could predict them before saying that word in my first language, so anxiety kicks in everytime I approach that word and makes the stutter even worse! In english on the other hand, I was not that exprienced to predict my stuttering scenenarios, so less anxiety leaded to less stutter. However, as I said earlier, I stutter same amount in english since I've become more fluent :)