I said if it does nothing, or tells you to swipe. I was not trying to explain all situations, I was trying to explain those two situations.

You seemed to mix up two examples, where one seemed to be a terminal not enabled for EMV, and the other one was a terminal enabled for EMV but which didn't "like" your card. But you simply reported them as if both were your card not working. As far as I can see, your card only didn't work in the second case, it was the terminal that was not yet fully enabled for EMV in the first case.

In the case where Chase card worked, did the Chase card work by insert or by swiping? Meanwhile, what exactly did the terminal do/say when you inserted your card and/or when you swiped your card?

Your AA card is an MC while the Chase card was undoubtedly a Visa, and MC's tend to have different (and longer) CVM lists* than Visa's do, and the second terminal perhaps may have had trouble with a method that was on your Citi MC card's CVM list but not with the "straight to signature" CMV list that's on a typical Chase Visa card.

*CVM stands for cardholder verification method. It's a list of methods such as signature, offline PIN, online PIN, no CVM, etc, that the card tells the terminal to try in a particular order. This list tends to different for cards from different banks, sometimes even for different cards at the same bank, sometimes even the same card from one time you get the card to another time you get the card.