I can relate to it, faced similar in group discussions, though I used to inform prior that I have a stutter so be patient with me, but not everyone complies to it, nor the interviewer considered it. I had got many rejections and heard a lot of people trying to make fun of me, even one professor in my undergrad tried to do that. In interviews I was always rejected in HR rounds, one HR directly told me you don't have communication skills so we can't take you. Sure, you go ahead with that post. It's still debatable about being considered a disability but still it's a condition people need to understand. You know when we speak and when we are about to stutter, the long pause or repetition of the sounds, when that happens, the other person makes weird faces, right? Have you noticed? The same happened when I was talking to the professor.