To be sure, you're referring to bank transactions that haven't been downloaded into QuickBooks Online? If so, let's manually update your bank connection to bring those transactions.
Here's how:
Go to the Banking menu or Transactions menu.
Go to the Banking tab.
Click Update.
You can also look at Starling's website for the following:
Check your account for messages, notifications, or alerts.
Check your bank’s website for any announcements about new security requirements.