Port Forwarding Not Accessible

I'm trying to setup a simple port forward on my XFinity router, and have found that the configuration has been disabled for some reason.

I went to the app, and the only thing I could it to do is send me this article: https://www.xfinity.com/support/articles/xfi-port-forwarding

Which is entirely inaccurate compared to the app itself.

The worst part is that it seems that someone had this issue 3 years ago, and the only change XFinity has made was to remove their workaround: https://forums.xfinity.com/conversations/xfinity-app/cant-port-forward/644b157d2715675987845b6b