Little Help About Fn_Get_Image

fn_get_image why doesnt get watermarked paths ?

$product_pair= fn_get_image_pairs(354, 'product', 'A', true, true);

its getting correct paths. with watermarked images.

$_image = fn_get_image(16727, 'detailed');

but this getting orginal paths. whats wrong ? also i tried detailed to product

also tried addon priority change nothing help