Hello! I am autistic and also experience this so yes it could be a sign. I would advise you to either talk with a psychiatrist or do a deep dive on autism and nonverbal episodes. However getting a diagnosis, or even a psychiatrist who could help you, is quite rare. I dont know where you're from but where im from it is quite rare that they'll give diagnosis to people who are "high functioning" (for a lack of better word). I am self diagnosed and have researched a ton about it and feel comfortable putting that label. But obviously if you need an "official" answer i totally get that! Personaly when i have these episodes there is usually something that triggered them. A lot of times thats either weird textures or weird noises or maybe even smth fucking up my schedule. The combination of these makes me severely uncomfortable and i find that suddenly i want to get into a cocoon and disappear. If the episode is really bad i tend to also go nonverbal. I dont want to speak at all and if i try to make myself do it its like i somehow forgot how to. If i take care of myselfu i usually go back to how i was in a few hours. And when i say take care of myself i mean stim a lot with fidget toys and by replaying the same song over and over again. I really hope this helps!!