The first thing we need to make sure is that your bank doesn't have any system maintenance, vcsltd.
System error in your bank can cause transactions not to download into QuickBooks Online. You'll want to log in to your bank's website to see if there are alerts or notifications.
Let's also update your banking. This helps to manually download those receipts.
Go to Banking and select the tile for the affected account.
Click on Update button.
Enter your Multi-Factor Authentication (MFA) credentials and select Continue update if prompted.