We have a web application that calls the following URL to authenticate with ArcGIS Server (which is federated with the portal). With ArcGIS Server and Portal version 10.5.1, it works fine—we can log in to the portal and get redirected back to the application. However, after upgrading to ArcGIS Servers and Portal version 10.9.1, we can still log in to the portal but are unable to redirect back to the application. Are there any differences in the "arcgis/login/?redirectUrl" API between versions 10.5.1 and 10.9.1?
Application calls the URL in following format.
https://<arcgis server>/arcgis/login/?returnUrl=<application url>
