Why is there no database connection when extracting WordPress?

Question

PHP

Hello! There was a question: I'm trying to unpack with a site created using the Duplicator plugin. The archive includes files and a database. For some reason, when I click on the "Test Connection" button, it says that it cannot connect to the database. In the terminal via SSH to the database with the same login and password, I connect successfully.
PHP version: 5.5.38, built by myself from source, mysql and mysqli libraries are present.
If anything, here is information about the PHP version.
All other sites on the server with PHP from the repository (versions 5.6 and 7.0) work fine, there is a connection with the database.
What could be the reason?

Answer 1

Specify mysql server not as localhost but as 127.0.0.1