No, it's pretty regular. It will even tell you to "try again" if you correctly don't select anything.

They probably assume that the vast majority of the population are not massive pedants and will do what they expect.

They probably don't assume anything, and it's just a corner case in their automated system.

Right, but it's why fixing it is not a priority.

That is, they assume the vast majority of the population is indistinguishable from their AI. I believe that view also informs their customer service procedures.

I think it's pretty clear what it's asking for and you are misinterpreting the request.