We have portal setup at a URL similar to the following "http://<portal url>/arcgis/home" through a reverse proxy. The WebContextURL parameter is set to "https:\\<portal url>/arcgis". Almost everything is working as it should. The only problem we are having now is when we try to create a an App using a template. The app creates fine but the resulting registered url is wrong. The URL ends up being something like this "http://<portal url>/app/..." which returns a 404 when you try to go to it. If you change it to this "http://<portal url>/arcgis/app/..." then the app loads. Why isn't it doing this from the get go? Can I change this behavior some where? I haven't found a spot to change this.