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I have a hook for one of my modules that worked just fine..
So my question is, how can i debug a not working hook?

use Doctrine\DBAL\Query\QueryBuilder;
use PrestaShop\PrestaShop\Core\Search\Filters\CustomerFilters;

public function install($delete_params = true)
{
	return parent::install() &&
            $this->registerHook('actionCustomerGridQueryBuilderModifier');
}

/**
 * @param array $params
 */
public function hookActionCustomerGridQueryBuilderModifier(array $params)
{
   # My Code
}

If i check the customer list using debug modus, the hook 'actionCustomerGridQueryBuilderModifier' is never hooked from my module.
But if i check 'Appearance > Positions' the hook is active!

How can i debug? Or what am i missing here?