Getting HTTP error 500 even if the account is authorised - html

Question

Having an issue with the database enabling on my cpanel.
I am using A2Hosting.
As I create the tables I get this error when I go to a page that uses it:
To try and fix this I added privileges to my account
here is my database code:
<?php
class config_db {
public function init() {
PDO('mysql:host=localhost;dbname="DATABASENAME";charset=utf8', '"USERNAME"', '"PASSWORD"');
return $db;
}
}
?>
After adding privileges I get this error:
Not sure why I still get an HTTP ERROR 500 after I have granted privileges
UPDATE:
As I checked one solution is to delete the plugins, but my cpanel files has none of it
UPDATE:
Creating a username and password that the database uses uniquely does not work either
UPDATE:
Deleting the .htaccess folder gets me a 404 not found problem
UPDATE:
There are no errors shown using inspect element or event in the cpanel
UPDATE:
The database is connected succesfully as I checked but the error 500 still persists

Answer 1

In A2Hosting please make sure you are using the correct database name. As per the documentation it should be:
When you create a database, your username is prefixed to the database name.
For example, if your username is abc, and you create a database named db, the actual MySQL database name is abc_db.
For more information:
https://www.a2hosting.com/kb/cpanel/cpanel-database-features/managing-mysql-databases