Unable to connect to instance with SQL plugin


I've read the documentation and searched for answers and comments, but still can't get my SQL plugin connecting to the SQL Server.

I have tried so many accounts and configurations, but nothing works. The client is running with a full access account, and the users I'm trying to use have all the privileges and roles on the database. However, whatever I input as credentials, I still get the "Unable to connect to instance", and no other trace.

My Netvault is on Windows Server 2019 Storage, the plugin is The client is a Windows Server 2019 hosting a SQL Server 2012.

Does someone have any clue?

Thank you so much.