Symptoms

The workflows are creating new Items in a List, and as desired, had been doing that and setting the author values to GlobalAdmin account for the Instance. Today, we are finding that the processes are using my credentials even when I am not running those workflows.
 

Diagnoses

The issue was caused by client credentials were used to renew OAuth Token when it was expired.
 

Resolution

Deleting the OAuth token from SmartForms Designer for the Service Account, and rerun the registration wizard with correct Global Admin service account resolved the issue.