Issue
Symptoms
Users are not being redirected to SSO login page while accessing Service Portal page
Release
Any release supporting Service Portal
Cause
As stated in below documentation, 'To use single sign-on with Service Portal, you must enable the Integration - Multiple Provider Single Sign-On Installer plugin (com.snc.integration.sso.multi.installer). '
Resolution
Enable the Integration - Multiple Provider Single Sign-On Installer plugin (com.snc.integration.sso.multi.installer)
Additional Information
https://docs.servicenow.com/csh?topicname=c_SPSSOLoginAndRedirects.html&version=latest