Raycast FilterDescendantsInstances makes result nil how to fix it?

        raycastParams.FilterDescendantsInstances = {mainModel}
        raycastParams.FilterType = Enum.RaycastFilterType.Blacklist

whenever I take off the filterdescendants it hits the HitBox itself but with the filter on it just returns nil https://gyazo.com/61d30487a8b94215f4323c26f7965b18 whatever player is in the hitbox (red part) i want it to shoot laser at but with filterdescendantsinstances it doesnt work i've tried literally everything but nothing works