I have a user pool with a configured Federated SAML IDP in Cognito’s AWS Console (User Pool > Sign-in Experience > Federated identity provider sign-in). Our users were able to login through this IDP in our Cognito just fine a week or so ago, now they are getting the following error: Invalid SAML response received: Unable to contact the configured provider. I already checked the following troubleshooting guides but they don’t have any information about this error

• https://repost.aws/knowledge-center/cognito-invalid-saml-response-errors
• https://docs.aws.amazon.com/IAM/latest/UserGuide/troubleshoot_saml_view-saml-response.html

I checked all configuration parameters on the configuration and they are all matching the expected values. The IDP has correct configuration for Assertion Customer Service URL, Entity ID, Name Identifier Format, certificates, and fields mapping. On the other side Cognito also has all correct configuration regarding URL Metadata, Field Mapping, User Pool Client attribution, etc. I tested in this User Pool a secondary configuration with a different IDP (Auth0) and that worked fine as well, this error is specifically about this IDP integration I mentioned which stopped working for whatever reason.

What is this error about and how can I fix/troubleshoot it?