Hello there, @IBTA22.

A possible reason is that the account was disconnected. If this is the case, your existing accounting data won't change. You'll need to disconnect the wrong account and reconnect the correct one. I'll be glad to walk you through the process.

These are the steps on how to disconnect an account:

1. Go to Banking and select the wrong account.
2. Click the pencil icon to edit, then select Edit account info.
3. In the Account window, put a checkmark next to Disconnect this account on save.
4.  Save and close.

Once done we can proceed to reconnect the correct account. Here's how:

1. Go to Accounting and select Chart of accounts.
2. Locate the name of the disconnected Account, then click the dropdown ▼ button and select Connect bank.
3. Sign in to your bank with your user ID and password. 
4. Follow the on-screen steps. This might include security checks your bank requires. It could take a few minutes to connect.
5. Choose the accounts you want to connect, then select the account type ▼dropdown. Choose the account type that matches your chart of accounts in QuickBooks.

You can visit this article to know how to use bank rules to automatically categorize transactions from your bank: Set up bank rules to categorize online banking transactions in QuickBooks Online.

The Community always welcomes you for further inquiries about bank connections. Have a good one!