Sorting is on mobile device different and wrong ???♂?

I accidentally noticed that the sorting is different on my mobile device than on the desktop, and I don’t know why.

On the desktop, it sorts correctly by modified date.

On mobile devices, it appears that the latest posts since May are missing.

I have tried it on different devices and also cleared the cash.

I have this function in functions.php:

function pa_change_blog_module_order($query) {
$pac = get_query_var(‘post_type’);
if (‘post’ == $pac) {
$query->set(‘orderby’, ‘post_modified’);
$query->set(‘order’, ‘DESC’);
}
}
add_action(‘pre_get_posts’, ‘pa_change_blog_module_order’);

The page I need help with: [log in to see the link]