Thanks for visiting our forum, here we mainly focus on general issues about Outlook desktop client.
Outlook is only syncing email and calendar events from the last 12 months
Do other users who also use g-suite email with Outlook have this issue?
As I know, there are two common options to help add g-suite email account to Outlook: IMAP account configuration or via tools like G Suite Sync for Microsoft Outlook. So, How did you add your g-suite email account to Outlook?
If you add your account directly by IMAP account configuration, the issue may be related to the settings of Mail to keep offline. Please check your account settings(File>Account settings>Account Settings>choose the account>change>Mail to keep offline), and try to take the time to All, then restart your Outlook client and wait all email items in the server to be downloaded to your client. However, IMAP accounts couldn't sync your calendars.
If you add your account via tools, I'm afraid that the sync settings may also be affected by the tools you used. You can check your Mail to keep offline settings firstly. If it still doesn't work , please try to contact with your tools support team for more information.