MySQL user not connecting

Problem:
Windows Server 2016, IIS Website, Setup a MySQL server/database, setup a WordPress website, quickly connect with root and root-password. Everything works fine!

Now you want things more secured, so you add a MySQL user with a password and rights to only the wordpress database. Change wp-config.php with the new login and you get a “Error Establishing a Database Connection” when accessing the WordPress website or admin.

Change back to root and the problem is solved. How to fix this?

Continue reading MySQL user not connecting