An entityFilter (not equal) doesn't work correctly when user can choose more than one option

EntityFilter works well when you can select only one option but in my case, I allow the user to choose severals option :

Now if I filter by not equal James Harveyd this is my result :

And the way I add my filter :

 public function configureFilters(Filters $filters): Filters
    {

        return $filters
            ->add(EntityFilter::new('supervisors', 'supervisors'));
    }

I don(t understand why EA make appear the second line, any idea ?