Hey Guys, its me again. Long story short: It wasn't the solution. It seemed to be it, but only because the output of ->connect_error is a string and cannot be used in an if, statement. I found the real solution, however. Here is a part of an email i wrote to my provider:
1. quoting from their article:
"Please pay attention to the capitalization of the letters "DB" when specifying the database name. A connect using "dbxxxx" will fail.".
This is wrong. In fact, any access made with uppercase letters will fail. These letters must be lowercase.
2. your example script uses the mysql_connect() command. This is deprecated since PHP 5.0 and has been removed in PHP 7.0. Therefore it does not work. Please change it to mysqli_connect, mysql or PDO().
3. your article always says that the user would be something like Uxxxxxx, and the database something like DBxxxxxxxx. This is wrong. In fact, the database is something like dbsXXXXXXX, and the user name is dbuXXXXXX.
Translated with www.DeepL.com/Translator (free version).
That is why it didn't work.
Also, yes, mysql driver is installed.