Have you ever tried speaking imitating a person or a different accent than your usual one? There is a chance you’ll stutter less. For some reason, we tend to stutter less when talking in a way that we are not used to. But then when we use that new accent or whatever too often, that becomes the “new normal”, our brain picks up on that and we stutter again with that accent. I assume it is similar with using a different language. As long as you don’t use it too often, there is a chance you could be more fluent. Of course, there is also a psychological aspect to it. When you are speaking in your second language, you know that people can expect that you speak slower and take your time to think what you want to say, since they are aware that you are not talking in your first language. With that pressure off your shoulders, you might also be able to be more fluent.