User Sync App will run manually but not on a schedule.

AD Sync logs (found in C:\ProgramData\Docuware\Logs\ADSync) show error:  "Password was saved with a different user account"

The user running the task in Task Scheduler must be the same as the Author of the task:

Either change the user to the same as the author, or simply recreate the schedule through the User Sync App.

This KBA is applicable to both Cloud and On-premise Organizations.