Background: We use AzureAD SSO for various web sites that support SAML currently. I'd like to expand on that and start enabling password based SSO for other sites. Our primary LOB app is served via remote desktop, and users log in through an RD Gateway / RD Web portal, so that is my first target for the password based SSO.
Issue: After adding the RDWeb page as an app and configuring password based SSO in AzureAD, the app shows up in my MyApps portal and I can click it to go to the log in page, but it doesn't fill in my credentials or log me in. The first time I went to the login page, AzureAD did prompt me to enter my credentials for the site (Though the fields on the prompt were labeled Param_1 and Param_2 instead of Username and Password). I can see in the AzureAD configuration for the app that it does appear to have saved the credentials and associated them to my user account, but other than that it doesn't seem to work. If I open this app again from the myapps page, it loads a microsoft URL first and then redirects me to the URL of the rd web portal, but doesn't fill my credentials or log me in automatically. I've reproduced this issue using Microsoft Edge v89 and Google Chrome v89, both with the My Apps Secure Sign-in extension v5.6 installed and signed in.
Any suggestions on what I may be doing wrong that would prevent this from working?
