@Sunshine It is T-Mobile NL. I'm waiting for their answer about (open/blocked) ports.

@Sunshine HI Sunshine, It works in 3/4G mode. The WAN IP is a public IP address. Thereof I could do management as https://public.ip/ when I set it up on port 443 But it did not worked as...

Hello, I can get Remote Management via standard 443 HTTPS, but if I choose another (non standard) port, the connection will time out. Any idea why it happens? Kind regards, LP.