I understand you created a separate user and database for your application, right? Did you follow our documentation?
You can get the grants that user has by running this command inside the database
SHOW GRANTS FOR 'YOUR_USERNAME'@'HOST';
I suggest you check your PHP code to ensure there is not any error there (The Apache's log should show more information if you are accessing your application using the web browser). Please note that LAMP and XAMPP do not contain the same components (MySQL vs MariaDB) and I don't know if you have the same PHP version in both your local installation and the cloud instance.