I have had that occur a few times. It has happened more than once because the connection “Burped”, and failed the transaction. A retry was all that was needed. I have also had it happen because the cashier didn’t know how to process the transaction properly, and it failed. It could be you just needed to give it another go. If you don’t get it to work with another try, you should check into it. Banks have had to do a LOT of reissues because of that. It could be that with so many, your bank may have had some overload glitch.