If PHP directive belong to “PHP_INI_SYSTEM” which means you can control directives under php.ini files. You can make changes in these directives in WHM.
For that you can follow these:
Login to WHM >> Software >> MultiPHP INI Editor
Another reason can be that if you are making changes in php.ini but the handler wants to use user.ini or .htaccess files then changes will not affect. So you have to check this.
You can check if handler loads php.ini or not by using MultiPHP INI Editor in cpanel:
Login to cpanel >> Software >> MultiPHP INI Editor >> Here you can check.
For that you can follow these:
Login to WHM >> Software >> MultiPHP INI Editor
Another reason can be that if you are making changes in php.ini but the handler wants to use user.ini or .htaccess files then changes will not affect. So you have to check this.
You can check if handler loads php.ini or not by using MultiPHP INI Editor in cpanel:
Login to cpanel >> Software >> MultiPHP INI Editor >> Here you can check.