KeyCloak using IIS reverse proxy

I have been attempting to set up KeyCloak (currently v 23.0.7) through IIS reverse proxy for some time now. I have modified every setting I can think of, but I can’t seem to get auth to work with my application. I can access the admin ui through https://fqdn:8443, but I’m seeing “Invalid Request” in the browser and HTTP/1.1 400 Bad Request in SAML-Tracer. Is there anyone who has successfully set up reverse proxy through IIS that may be able to provide any guidance? I am NOT a developer of any kind (GIS Systems Engineer), so I’m certain this is operator error…but I’m stuck. Any help would be greatly appreciated!!