I can help you resolve the connection issue between your bank account and QuickBooks Online (QBO), @manager-cwspring.

Before doing so, can you tell me the name of your bank? This way, we can verify if there's an ongoing investigation related to your financial institution. 

There are times when you're asked to enter your Multi-Factor Authentication (MFA) code when updating your bank account. However, not all financial institutions require this. If you're unable to download the recent transactions, the issue may be on your bank’s end. I recommend signing in to your bank’s website to check for messages or alerts. It's also possible that the bank is performing system maintenance.

Here's how:
 

1. Go to the Transactions menu, then select Bank transactions.
2. Click Link account. You won’t add an account, you just need the listed URL.
3. Search for your bank and select it.
4. Copy the URL listed for your bank.
   
   
    
5. Sign in to your bank's website using the copied URL.

If everything looks good, go back to QuickBooks and manually update the account again. If you make changes on the website, update your bank account sign-in information in the system. For more details, please see this article: What To Do If Bank Transactions Won't Download. 

If this doesn't work, let's log in to your QBO account using a private or incognito window. Sometimes too much cache build-up in a browser can cause unexpected behavior with the product. This can be the reason for your bank connection issue. Here are the following keyboard shortcuts:

• Safari: Command + Shift + N
• Mozilla Firefox: CTRL + Shift + P
• Google Chrome: CTRL + Shift + N
• Microsoft Edge: CTRL + Shift + N

You can also use other supported browsers like Firefox, Google Chrome, Safari, and Microsoft Edge to find out what computer and browser you need for the best experience when using QuickBooks.
 

In case you're still unable to link your bank account, you can manually upload your bank transactions to your QBO account as a workaround. To do this, you'll need to download the entries from your bank's website in a CSV file format. Then, import these transactions once ready. 

Please keep me posted on your progress in getting this issue resolved, @manager-cwspring. I want to ensure your bank will be connected permanently to QuickBooks.