Children are usually cooperative unless they're hungry, tired, ill, or emotionally unable to do what a parent requests. Which they usually do since they want to grow up, to behave in an adult fashion.
When a child continually misbehaves it is always because they are unhappy, because their parents are not providing what they desperately need. Yet determining this may not be simple and require professional advice. My suggestion about this: if the clinician revels in jargon, is unable to explain in easily understandable language why your child is unhappy and what need be done to remedy it, find another specialist! You are the customer who need be satisfied and not the other way around.