Hi Jarred, Welcome in Community
The most effective way to resolve this is by performing a complete permission reset. You should start by visiting your Google Account Security settings to remove "Microsoft apps & services" from your third-party access list (Don't worry, this won't delete your emails; it just forces a fresh handshake).
Once that is cleared, remove the Gmail account from your Outlook settings and re-add it from scratch, making sure you manually check the box that allows Microsoft to "Read, compose, and permanently delete" your mail during the browser-based sign-in process.
Furthermore, you must verify that your Gmail labels are correctly configured to appear in external clients. Since Gmail uses labels instead of traditional folders, you need to access your Gmail settings in a web browser, navigate to the Labels tab, and ensure that the "Show in IMAP" checkbox is selected for every folder you wish to sync with Outlook.
Let me know how it goes
Elvis