Sudden extreme stuttering at 5 yo

Sudden extreme stuttering at 5 yo Just wanted to tap into this community in case someone could relate- recently my 5 yo began sporadic episodes of severe stuttering - such as saying the word “what” over a dozen times at once, needing our intervention in order to stop. Honestly it was frightening. I asked him what it felt like and he said he cannot control it. He has been in speech therapy for articulation and fronting issues but this is the first time he has shown concerning stuttering. He may have adhd and/or level 1 autism but yet to be officially diagnosed if that’s of any relevance. Has anyone experienced or seen anything like this? Suddenly stuttering?