User can't log onto Smartsheet Using SSO

I have a user who is unable to logon using her MS Azure AD. All other users have had no issues. The error message she receives loos like this:

Our ITS helpdesk has checked her email settings and everything looks ok on her settings. She is able to get into other web-based systems we utilize using SSO (Workday, Salesforce, etc.). Anyone have any ideas? We only allow SSO active users of our organization. All other users outside of our organizations are invited as editors, commenters, or viewers of specific workspaces, sheets, etc.

Answers