You can manually update the downloaded bank transactions. On the Transactions page. and then the Banking tab, click the Update button in the upper-right corner. If the missing transactions are still not yet showing up. Do this at least three to five times to ensure all of the transactions come through. Another thing to look out for is when your bank has a maintenance update or if there are important notifications from your account. They can prevent your transactions from downloading into QuickBooks. Contact your bank to see if this is the case.
If you have questions regarding specific transactions, highlight them on your statement. Often you can go online and find out more about the transaction, as well. When you have this information ready, it is much easier for the customer service representative to help you. Transaction identification numbers can also give the bank the information it needs to start looking into the issue.