Anyone using calendar integration with Office365 may be interested to know that development work is proceeding with this ticket. [FREEPBX-23749] Support Microsoft 365 Modern Authentication for Calandar Sync - Sangoma Issue Tracker
If you have the ability to test and comment before it gets published to edge, please see the links in the ticket for installing the module using the command:
fwconsole ma downloadinstall <URL>
To revert the change you can install from the repo with
fwconsole ma downloadinstall calendar --force