Hi there, @juliecottam.
You'll want to re-download the transactions to get this fixed. Let me walk you through how. You can use the Web Connect file to download manually. Please see this link for the detailed steps: Manually upload transactions into QuickBooks Online.
After that, verify your bank register to see transactions. I'm also attaching these handy articles in case you want to do the following.
Should you need further assistance, don't hesitate to leave a comment below. We're always here to help.