A security engineer is implementing authentication for a multi-account environment by using federated access with...

A security engineer is implementing authentication for a multi-account environment by using federated access with SAML 2.0. The security engineer has configured AWS IAM Identity Center as an identity provider (IdP). The security engineer also has created IAM roles to grant access to the AWS accounts.

A federated user reports an authentication failure when the user attempts to authenticate with the new system.

What should the security engineer do to troubleshoot this issue in the MOST operationally efficient way?