@kisberes 

Hi,

Maybe try the following procedure.

- Disconnect all your client devices from the router and make sure they can't reconnect automatically.

- Reboot the router.

- Connect only one client device to the router that you use to access the router's configuration GUI. (do not use the client device that is running the service that requires port 44158 to be opened, because this device might try to open port 44158 on its own via UPnP)

- Once you have entered the configuration GUI try again if you can setup port forwarding of port 44158 now.