Few possible reasons why bank transactions are not downloading is that, your financial institution may have undergone system maintenance. Or, you updated anything on your bank’s website without updating your bank info in QuickBooks.
We can fix this by manually updating your bank account to refresh the connection.
Go to Banking on the left menu.
Choose Banking tan
Select Update.
Otherwise, I recommend checking your bank's website to verify if there are ongoing maintenance.
If it's because you've made changes on your bank website, make sure you update your bank info in QuickBooks as well.
Select the blue tile for the bank account, and then select the pencil icon to edit.