Issue: A specific realm cannot send SMS, Voice, and Push notifications through HTTP URLs in System info tab though for other realms it is functioning properly.
Cause: There is an issue with the cloud being able to properly read through the message level encryption that is attached to the URL. If it works for other realms with the same setting, we know it is not a network issue and a setting within the appliance that is causing this issue.
Resolution: Make sure to check the permissions on the certificate.
If the proper permissions are there, check the authentication methods within IIS for that specific realm with the issue. Make sure that only Forms Authentication and Anonymous Authentication are the only enabled status for the realm. In the past, we have had customers who had ASP.NET Impersonation enabled with Anonymous Authentication/Forms Authentication enabled which is not the correct configuration. This can cause complications on what kind of authentication method is being used, thus not being able to properly pass the message level encryption on the 2nd factor.
If those two settings are correct and it still does not work, a work around would be to switch the URL in the System Info tab to https instead of http.