Hello Mohamed,
indeed it came from SEF option turned on in global configuration. But meanwhile I think I solved it myself. I double checked if all the category listings, menus and products listings are synced and linked together (Hikashop option in the module/menu page). Then I opted for Use canonical URL and generate if missing. I don't remember any other things, but I for sure didn't turned off the SEF Joomla. And now it works, because canonical urls are connecting the missing links. Hope that might help some others.