Multiple Single Sign-On(SSO) for login with Adobe Learning Manager

When I attempted to migrate the SSO set up in the sandbox to the Production environment, I encountered a 503 error with the message: 'Error: No user details found for the email id. Please check with your admin if you have an active account in Adobe Learning Manager.' Why is it functioning correctly in the sandbox, but there is an issue in the Production environment? There is an internal user with the same email in Adobe Learning Manager.