You feel small or stupid around them
You walk into their office competent and walk out feeling like a junior who got it wrong.
Rule out first
They really may know far more. You may be new to the role. A strongly hierarchical setting.
What could explain it
Dominance and prestige: They keep status by intimidation (interrupting, sighing, questions designed to expose) rather than by earning respect.
Grandiose narcissism: They need to feel superior and do it to most people; you'll see the same effect on others.
Envy: They cut you down specifically, and it started when you began to do well.
Transference: They remind you of a parent or teacher who made you feel small; the effect is stronger than their behaviour explains.
Defectiveness/shame schema: You feel small with many people in authority, not just this one; the feeling is waiting for a trigger.
Interpersonal complementarity: Everyone goes quiet around them, not just you: their dominance pulls submission from the room. Staying warm and holding your ground for a few exchanges changes how they treat you.
A next move
Ask others how they feel after time with this person. If they feel the same, it's them; if not, look at your history and who they resemble.
If it’s you
Who made me feel this way first?