PayPal Extras MasterCard won't activate One Step Update

cbit

This has been a problem for months. Quicken Classic Deluxe for Windows stopped downloading transactions for my PayPal Extras MasterCard with Synchrony.
I can detect, connect, and download transactions for my PayPal account, but Quicken doesn't detect my MasterCard account anymore. Trying to activate my previously working MasterCard account results in the error below. I think everybody knows that you can't login via web browser to the credit card account without logging into PayPal first. So, what's the deal, Quicken?