This is a tough line to walk. Just by the situation you put forward, it's not actually enough information to even form a decision. From my experience, there is something bigger going on. The behavior mentioned is indicative of someone that does not feel valued, that feels defeated. They are not comfortable with management. Ignoring this makes it worse. Asking them 'what their problem is' makes them defensive. Never put someone on the spot to explain it reinforces the defensive behavior. Just a thought though. Your post is informative and you do have some valid points.

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