Cannot connect to a remoter SQL Server via SSMS

Hello,

I'm working on two VM connected through virtual private network (pings do work). One of them has a WINCC SQL Server instance running and the other tries to connect to that server, and consequently to the databases of that server. Although I have followed next url's steps https://www.sqlservercentral.com/articles/setting-up-management-studio-for-remote-sql-server, I get errors when login: 0, 18452, 18456. I also have tested with different configurations but without succeed.

Can anyone help me?

[POSIBLE SOLUTION: I didn't restarted the server after enabling SQL Authenticaiton in server properties. Now it works although the server remotely connected appears with a red circle.]