I’m sorry you are having so much difficulty in getting a diagnosis. I am beginning to wonder if the professionals cannot engage or interact either ( other than with themselves). It is a long list and you have highlighted so many points of concern that I share your frustration that they will not at least try to look a little deeper so that you can get the assistance you need. I may be wrong but I am getting the impression that professionals think there cannot be much wrong if the child can speak well at least superficially.
I wish I lived closer so I could help !