Picture quality at the Masonry Galerie

Hi all,

please check the picture quality at the Masonry Galerie at the “PREVIEW SPRING SUMMER 2021” There are 2 Pictures.
https://www.samoshoes.com/cinque/
If you open (Lightbox) the picture then its sharp but in the preview the pictures are very unsharp.

I also added this code in the function.php, but it don’t work:

add_filter( ‘avf_avia_builder_masonry_lightbox_img_size’, ‘enfold_customization_change_popup_size’ );
function enfold_customization_change_popup_size( $size ) {
return ‘fullsize’;
}

What can I do?

Thank you.

Cheers,
Harry