Yeah honestly its pretty weird I honestly used to have complete fluency until sometime during high school. I noticed a stammer (speech blockage) that got progressively worse over the course of several years. Its been almost a decade and I still have the stutter, its like a toxic friend that I just can't get over. From my personal experience there simply seems to be lack of research on stuttering and when I talked to doctors they simply assumed it was caused by either physical or psychological trauma but in the end just ended up blaming it on stress from school.