I assume you have set up that taxonomy in a similar way to the two that are working.
It's not easy for me to tell just looking at the front-end what the issue could be, and it would be quickest if I were able to look directly at your site rather than exchanging screenshots etc.
Let me mark your next reply as private so that I can get log-in credentials from you—you may want to create a temporary admin user for me to use that you can later delete. And be sure to have a current backup of your site, even though I don't intend to make any changes.
The Query Filter section ("Filtre de requête") is normally hidden on a custom search View, but I exposed it using the Screen Options tab at the very top of the page.
You can see (screenshot) that it only includes two taxonomy filters, even though you have inserted the filter controls for three taxonomies.
Something went wrong inserting the "Secteur d'activité" taxonomy filter or it was later deleted.
In any case, you can fix the problem by deleting the filter control from the Search and Pagination section and then inserting it again.
Double-check that the corresponding Query Filter is inserted, and that should fix it.