I can't connect client/server over internet

Hi, i’m trying to connect my Server in a NAS with a Windows computer in another network. I’ve enabled the internet mode on the server, and configured the settings like i’ve seen in one post and then i’ve downloaded the preconfigured client and installed in the windows computer (client). But the client says that the server is unreachable and the client shows offline in the server.
I’m using a DNS like you can see in the photo, teorically the DNS is correctly setup, but i don’t know how to know it at 100%.

I’m having the same issue with remote clients.