AMEX credit card verification freezing

I've been having issues with AMEX credit card verification for a few weeks.

1) Getting the prompt for multi factor authentication is INCREDIBLY slow -- it takes 2-3 minutes before the prompt screen comes up.

2) Once I request the SMS code, the verification screen freezes at "Validating your answers" and a blank window that says "Processing". It never gets to where I can enter the SMS code (or let it transfer from Messages)

I know AMEX is switching to updated verification, so maybe this is transitory, but right now, AMEX multi factor authentication on Quicken for Mac DOES NOT WORK.