Not working on smartphones

Hi, i installed this plugin, and inserted into header.php file via shortcode in this way:

<?php echo do_shortcode('[woocs]'); ?>

And on desktop PC works well, but not on mobile devices. When try in mobile device, it show dropdown, but when press on any language, it is not changing at all.. Seems like not react.. Read also that premium version have the same issue, so im scared to purchase because of that. ANy help?