Calendar Sync Issues Office 365. Before delving into the solutions, it’s essential to understand the common causes behind outlook calendar not syncing. I am using macbook pro 2020 with macos catalina 10.15.6 and outlook for mac version 16.39 (20071300).
In the outlook app, go to settings> tap the account that is not syncing > tap reset account. Verify if you are using the correct outlook account.