Hello there, tron101,
Is there a specific banking error you encountered while trying to connect the credit card account?
Let's make sure the correct account is selected. Furthermore, the bank login credentials also needs to be accurate.
Check this article for more information: Connect bank and credit card accounts to QuickBooks Online.
Here are some common banking errors and how to fix them:
Please let me know how it goes, I'd love to be more of help.