1. Check the settings on your Apple Watch to ensure it is synced with your Microsoft calendar.
2. Make sure the software on your watch is up to date.
3. Check to confirm your account info for the Microsoft calendar is correct and that all event settings are updated.
4. Uninstall and reinstall the Microsoft calendar app to refresh the connection between the watch and the calendar.
5. If none of these solutions work, contact Apple support for further assistance.