One time an HR drone told me it was policy to ask and he didnt know why. I quizzically asked him why as an HR rep he didnt understand the HR policies of the company he worked for. I even asked him if it was policy for HR to not understand HR policy.
I kind of wished I'd told him that I'd recorded this phone call for training purposes :/
It's amazing how sweet and polite you can be with this line of questioning and how humiliating their answers will be (because there is no good answer).
It's a massive red flag so I doubt ive lost any good jobs this way.