So learning to be still and quiet, to be sensitive to non-performance body language, to look for natural shifts in attention before interrupting, to be patient and give kids time to cogitate before responding... those will all help you have a better handle on what's going on with your kid. Unfortunately, those are all exactly the opposite of the kinds of parenting behaviors most of us have seen modeled - and other parents may well criticize you! Kids are "supposed" to respond - promptly and pleasantly - to adults When they don't, adults tend to take it personally and retaliate. So it can also help a whole lot to remember that thoughts and feelings aren't the same as performance! A person can feel respect or gratitude or kindness or care without being able to perform the necessary social cues to standard.
None of these things are limited to neurodivergent kids, btw. They're really variations on... well on good parenting in general. Listening to kids, striving to understand where they're coming from and taking their thoughts and feelings seriously matters with All children. Making it easier for kids to explore the world in ways that work for them is good for All children. It just doesn't always look like you expect it to
(When I was a kid and a teen, I remember being shouted at for taking too long to answer a question - usually not from teachers, but definitely my parents and from other teens. Working retail helped me learn to have a set of "stock" answers that I could just blurp out at people. Living with Mo, I've learned to wait as long as she needs and not expect a response in words. But I've also seen her practice greetings, conversations, rehearse pleasantries. Now that she's a teen she's not as obvious about it as when she was little, but there's a big difference when she gets even an hour's prep time before having to deal with someone new. The other day we had someone over to look at our cable internet, and I'm sure the cable guy didn't even think she was "shy" - she was able to step up and tell him what was going on better than her technologically backward parents )