Hi
The issue was caused by an override of the JA Megafilter plugin for Virtuemart in your template. I’ve updated the following file to resolve it:
root/templates/ja_brickstore/html/plg_jamegafilter_virtuemart/default.php
I've attached the updated file for your reference. The filter page is now displaying products as expected: [your-site-url]/filtrer-les-produits
Kindly check.