This document details Authenticating using Duo for email and calendar on an iPhone may cause the calendar complication on the Apple Watch to be out of sync. Below are the instructions for fixing this issue.
Related KBs
Campus Email - Setup on iOS (iPhone, iPad, and iPod Touch)
1. Re-authenticate your campus email account when prompted on your iPhone.
2. Open the Watch app on iPhone.
3. Select "General."
4. Select "Reset."
5. Select "Reset Sync Data."