Why is it impossible to remove port-forwarding on Xfi gateway

Since I switched to the new XFi Gateway I am not able to access the gateway admin anymore. So I am supposed to rely on the Xfinity online portal to edit the ports I want to edit/open on the gateway. At this point I have tried numerous times to delete a port that is open to one of my devices but every single time the response is a waiting and failed, restart your gateway. 

Any ideas why this is happening?

Thanks