VCF Automation 9.x
VCF Automation Tenant Manager attempts to match users by either their full email address (including domain) or by a substring of the username (without domain). If the username is not part of the email address then the project assignment can not be resolved and causing this issue.
To resolve this issue, reconfigure the OIDC mapping in the Identity Provider to ensure the username and email address fields match.
Workaround: Assign users to the project via a Group rather than individual accounts. Group-based synchronization in the Tenant Manager resolves memberships differently and is not affected by individual username/email mismatches.