Let me help you fix the overstated bank balance, @Marja Kleynhans. 

Possibly, the process created duplicate transactions. That's why the result of the bank balance is overstated. Also, it could be that there are new transactions added to QuickBooks ( new transactions will be added automatically for a connected account). This results in having an overstated or new bank balance in QuickBooks as well.
 

First, you'll need to manually record a payment to the open invoices. Afterward, make sure to match the bank transaction to the paid invoice.

Please note that when QuickBooks downloads bank data, it tries to find a match with any QuickBooks transactions already entered. If you agree with the match information shown in the row, you only need to click the Match button. This will match with the existing QuickBooks transaction. 

If not, you can match or categorised them to the correct transactions by utilizing the Find match option. 

For more details about handling bank transactions, you can check this article: Categorise and match online bank transactions in QuickBooks Online.

Also, you can get more points from these articles:

• Learn the reconcile workflow in QuickBooks
• How to fix differences between QuickBooks balance and bank balance.

I'd be glad to hear if everything's balanced. Don't hesitate to comment below if you need further help. Take care and have a good one, Marja Kleynhans.