Infinite Scroll ignores custom shortcode on childtheme

Hi,
i built a chip theme based on twenty twelve with a custom short code defined in my theme/functions.php

on the first entries the short code works well, but on the pages loaded by infinite scroll the short code is ignored or still doesn’t work.

http://www.kunstclub13.org

it just wraps the post-thumbnail with a link to a external gallery.

any help? thanks!!!

https://ww.wp.xz.cn/plugins/infinite-scroll/