[Mz]

You are taking my remarks a bit too literally. And your experience in a pizza place and my son's experience are entirely different things. Coaching him on what to say does not solve it.

We have done a lot of reading and we believe he lacks prosody and lacks the ability to tone match. This is something other people are not consciously aware is socially important, but he routinely gets that reaction that is summed up by the phrase "I don't like your tone."

In contrast, I appear to habitually tone match without trying. This gets me read as incredibly deferential, which has a different social downside. So, one thing that does work is he and I frequently shop together, everyone knows I am his mother and people generally find me likeable. They eventually conclude "He's a nice, quiet young man." and quit having an issue with him being him.