Thank you for
reaching out on the community and telling us about your issue. Quicken will normally download the last 90 days worth of data. A lot of banks support downloading transactions into quicken via a Web connect file(QFX). If you go to your banks website see if there's an area that lets you download/export transactions and make sure you select the correct dates/format. Once you do that you should be able to import them into quicken and get all the missing data.
Please let us know
if this helps resolve the issue for you.