The issue has been resolved. SSO login functionality in the us-east-1 region has returned to normal, and all services are operating as expected.

We have rolled out a fix for the SSO login failures affecting the us-east-1 region. We are monitoring the results and will continue to observe the service to ensure stability before resolving the incident.

We have identified the cause of the SSO login failures affecting the us-east-1 region and are working to implement a fix. We will continue to provide updates as progress is made.