Problem with count after filtering product

[ubeo]

 Hi, I'm using an observer for product collection filtering on catalog_block_product_list_collection (Magento 2). The product collection shown is OK and the filter works correctly showing only the filtered products. The problem is at the pager / count level. I have the full collection count on the pager (by example 15 Items) and only 10 items are show in the product list (which is correct). Here is the code :

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/Event/etc/events.xsd">
    <event name="catalog_product_collection_load_before">
        <observer name="catalog_product_collection_load_before_test_productfilterbrands_observer" instance="Test\ProductFilterBrands\Observer\FilterTrigger" />
    </event>
</config>

class FilterTrigger implements ObserverInterface
{
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $collection = $observer->getEvent()->getCollection();
        $collection->addAttributeToFilter('entity_id', ['nin' => [2]]);
        return $this;
    }

}

 Thanks for help !