American Express "Invalid Input" Error

Roger_B Member ✭✭
Edit: In the immortal words of Emily LaTella, "Nevermind."

I use Firefox containers, and both Amex and Quicken are in the "Banking" one. Apparently, something goes sideways during the authentication process and communication either fails or is incomplete during the transfer.

I deleted the Banking container, tried again, and it went through.

I'm switching my Amex cards from Direct to Quicken Connect as requested by them, I get to the Amex website, select the cards I want, and click on continue/okay. Amex comes back with "Everything's Hunky-Dory! Sending you back to Quicken" and Quicken is "Uh-uh", returning:

"Please try again later.

Care Code: invalid_input

Empty SessionStorage on browser redirect"

I've disconnected from Amex as recommended in another post and tried several times. Everything works fine until I return to Quicken where it dies.
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