Issue Summary

While configuring SAML with auth0 IDP, a user cannot save SAML configuration on the Atlassian organization.
This happens only with organizations with flexible authentication policies enabled.
IDP auth0 provides Entity id in URN format: "urn:TENANT.auth0.com."
Refer auth0 documentation.
Saving configuration with URN format returns "Error: issuer must be a valid URL."

Steps to Reproduce

1. Open SAML configuration page on the organization that has flexible auth policies enabled.
2. Enter Entity id in URN format, some sample SSO URL, public certificate, and save configuration:

Identity provider Entity ID => urn:TENANT.auth0.com
Identity provider SSO URL => [https://TENANT.auth0.com/samlp/APP_ID]

Expected Results

SAML configuration should get saved.

Actual Results

SAML configuration does not get saved with the below exception thrown in the console logs:

"code":"BAD_REQUEST_FORMAT","message":"Error: issuer must be a valid URL"}

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available.