I am Using MacBook Pro 2020 with macOS Catalina 10.15.6 and Outlook for Mac version 16.39(20071300).
I have office 365 account (official). When I configure that account - email works fine, but Calendar sync has an issue. It keeps showing "sync is pending for this folder" and then for some time will show "downloading items" and after some time will show Not connected to XXXX@XXXX.com I have reconfigured twice, tried "Empty cache". Nothing is working. Any help will be appreciated.