Forward login hint to Microsoft Entra ID with SAML Connection


I have set up an SAML enterprise Connection where the IdP is Microsoft Entra ID (Azure AD). When users login to our system they have to first put in their email on our side and then also on the IdP side, which is of course bad user experience.
I am trying to forward the login hint but as it seems this is not supported for SAML and Microsoft Entra ID.

I found that you can include the login hint in the SAML request Subject in SAML Request. This is not working since Microsoft for some reason decided this shouldn’t be the way to do it. Instead you should supply it with a Query Parameter according to this their documentation for SAML Subject

I looked into the Auth0 Documentation of how we can supply parameters in the login request to the IdP. I update my SAML connection with an upstream parameter and it went through but I am not seeing the login hint forwarded. In the documentation it also says that “SAML IdPs do not support upstream parameters” so I guess that Auth0 is not adding/sending any upstreams paramters even though the paramters exists in the SAML connection Options.

Is there anyway to solve this?