If the steps above do not resolve the issue, please contact Quicken Support. Phone support is available from 5:00 am PT to 5:00 pm PT, Monday through Friday.
I have the same Issue with Synchrony Bank Amazon Store Card. I have two cards with Synchrony. The other is a Lowe's card. I've tried disconnecting both cards from one-step update. Closing Quicken for Windows. Restarting Quicken. Then connecting the Amazon account. When I do, Quicken asks to link to both accounts. And does that without error mesages. However, only the Amazon store card shows up in One-Step update list of accounts. And the cc-800 error still occurs on every One-Step Update.