Thank you for taking the time to visit the Community to post your issue, although I apologize that you haven't received a response.
We will need a bit more information to be able to assist. Please take a moment to review the information here and post back with the year and version of Quicken you are currently running.
Are the transactions missing from just the reconcile screen or from the account in Quicken? As in this transaction were not downloaded?
The more information you can provide regarding this issue will help the Community to better understand and assist.