Hi,
Please try re-adding the Outlook calendar. I suggest using the web browser if you are not using it.
If you have already tried it, please check the time zones between your Outlook and Google. Make sure that they are aligned.
In Outlook on the web or Outlook.com, open the Settings menu and verify that the time zone selected there is the same as the time zone configured in Google Calendar. If it differs, please try to change the time zone to match Google calendar and and wait for it to synchronize. Also, try re-adding again.
If you need more assistance, please let me know.
Stay Safe!