Citect SCADA 2018 WebClient issues

If we are using web client in same machine than the web server, the issue does not happen.

Could be several things, but my best guess is that something like a firewall is blocking the Citect TCP ports on the server. Could be a firewall on the server or on the client, or some external firewall in the network.
On the server, just make sure incoming traffic is allowed to TCP ports 80, 2080, 2082, 2084, 2085 and 5482.

Hello, tank you for your answer.
You are talking to create a new rule to allow the ports described are open to incoming data?

The port established in server with client is 80. the others ones indicate the loopback ip address.

Yes, try creating a new rule. Or turn the server firewall off, only for a test.