I opend ports for arma 3 and i tried to add it to portforwarding,i click add and the add button goes gray and does nothing i check if the ports were open and they wern't. So i remove all the things that had the ports opend (e.g dying light) to see if it may be conflicting with arma and it didnt work so i tried to add the applications but it wouldnt add them back.
I found the Hub3 port forwarding rather hit or miss in short time I used one. Best bet is to try a factory reset using the recessed button on the back, hold for at least 20 seconds. That might improve things and let you set your forwarded ports again.