Labels aren’t helpful. When you label, diagnose or attribute a negative personality trait to your partner, you begin to believe that they can never change.
Rather, describe the behavior that you are noticing. Be realistic about how often it really happens. And be curious about triggers might be prompting the different behaviors. “Sometimes he withdraws and sometimes he interacts with me. Let me ask him what might lead him to withdraw.” “Sometimes she is in a great mood and sometimes she is grumpy. I wonder what is happening for her at those different times.”