Trouble with remote desktop and entra app proxy

Question

So I am at my wits end at this point. I have been beating my head against a wall for the last two weeks with setting up an RDS deployment with Entra App proxy. Regardless of what I seem to do I end back at the same issue. The end result is when I try and launch a published app from the webapp, I land with getting this error immediately. "The connection to the remote PC was lost. This might be because of a network connection problem. If this keeps happening, ask your admin or tech support for help." Jokes on them because I am both of those things! I have been on the phone with microsoft twice now, who dont know what the problem is, but both of the people I was on the phone with know that its not their department that is the issue so I am waiting on my third person to talk to. I have tried this with a few different scenarios. One with the Web Server and the Gateway Seperate, one with them together. One with the entra connecter installed on the web srver, once on the connection broker and once on a seperate server entirely. I am using a publicly issued cert from go daddy for the all of the rds roles. its bound to port 443, I have gone through this walk through https://dectur.com/rds-aad-proxy/

and this from Microsoft

https://learn.microsoft.com/en-us/entra/identity/app-proxy/application-proxy-integrate-with-remote-desktop-services#direct-rds-traffic-to-application-proxy

and this one,

https://parveensingh.com/publish-rds-environment-with-azure-ad-application-proxy/#configuring-user-access-for-the-application

All have ended with the same result of having that error message. Then if I try and download the RDP file and launch it I get 'your computer can't connect to the remote computer because authentication to the firewall failed due to missing firewall credentials.' I have engaged every serach i can think of, chatgpy for days on end. I have been deep in the settings in IIS and Remote Gateway manager and still stuck in the same boat. Any help would be greatly appreciated.