Installing old WP site on new server

I am changing servers and trying to install some WP websites. I have done this several times with other servers so it’s not new to me, but on this server, for the first two WP sites, I am getting an Error establishing a database connection.

I have tried importing the database from backup, didn’t work, so I deleted the database and user, and re-created it.

wp-config.php file is using the correct usernames and passwords on localhost. I tried using mysql.domainname.com instead of localhost but that didn’t work either.

What am I missing?

Thank you!