So, because gnome hasn't designed the interface for firewalld the solution is to disable it until they do create one?
The firewalld interface isn't bad except fur one annoying thing: the tricky runtime/permanent modes. That should be made clearer. Other than that, guess what? Networking is just really complicated and trying to guess what's right and then not exposing the necessary manual configuration tools to fix it means that, like most gnome tools, it either just works or you have to dig into non-gui solutions (and for networking that can be, as I said, very complicated). That design pattern might be gnome's biggest weakness and lack of manpower is no excuse. This is really, simply, a design issue. They've no interest in exposing these things, regardless. If they're auto-detection doesn't work, file a bug, and in the meantime live with a broken system
Sorry for the rant. I find myself becoming less generous towards gnome the more I hear about them.