Have you ever been accused of faking your stutter/stammer?

Have you ever been accused of faking your stutter/stammer? It’s never happened to me personally, although there have been times when people have pointed out that I said a sentence fluently, but I’m not sure whether they said it out of surprise or suspicion. If you have ever been accused of faking it, was it in a one to one interaction or in a group, and were you able to prove that it was real. I understand that trying to prove something which you wish you never had is a horrible feeling, and hope that no one has to face such a situation.