Wells Fargo Credit Account

I can't speak about the internal workings of Quick Pay.
If you haven't done so already, contact Quicken Support on the phone during posted hours of operation and request help. Let them do a screen share session with you to review the situation on your computer, to determine the nature of the problem and to figure out how to fix it.

Instead of using Quick Pay or Check Pay, how about logging on to the WF website to make a one-time payment directly?
Or, alternatively, set up and use the bank's Autopay feature to let WF make automatic monthly payments on due date as direct debits from your checking account.
In Quicken unlink the reminder from Quick Pay / Check Pay so that it becomes a regular (offline) reminder. Record it before due date and before you download transactions from the bank containing the transfer confirmations and you're all set.

I've been using all the billers, banks, credit card and mortgage corporations' websites, making use of their AUTOPAY (APS, Direct Debit, etc.) service. This way, for almost all of my regular payments, the current one and all future payments, will be debited on Due Date directly from the checking account or a credit card account, where applicable.
In parallel to that, in Quicken, every month, I record a regular Scheduled Reminder to keep track of the payments before they come due.

This way, for many years, I've been able to take care of all my payments automatically, even during times when I was travelling overseas and didn't have easy access to the Internet. Haven't missed a payment in a very long time.