Allow me to address this bank connection concern and get you back to business.
We haven't received any reported cases about connection issues with Regions Bank into QuickBooks Online. For now, we can try logging into your QuickBooks account through a different supported browser. It will help us determine if the problem is related to the browser's settings.
However, if the issue persists, I'd suggest running the manual update to refresh the connection between your bank and with QuickBooks.
From the left menu, select Banking.
On the Banking page, select Update.
If prompted, enter your Multi-Factor Authentication (MFA) credentials and select Continue update.