We are working with the new Workforce application in ArcGIS for Enterprise. I have created a new 'headless' user account through the 'add built-in portal members' option, specifying the username and password, as there is no enterprise login (no email address) for this user. We use the headless account in the various python assignment scripts available on GitHub, for use in a task manager, etc. Whenever I try to sign on to Portal with this new username and password, I keep getting prompted for credentials. I can see the user in the Members page in Portal and access the various manage and view options for this user profile. I even went so far as to reset the original password, but I am still unable to sign on. We have used the same idea in AGOL successfully. I hope this is something simple I am overlooking. Any help would be appreciated. Thanks in advance.