Thumbnails on mobile devices

Hi,

Since the update, responsive re-sizing of the thumbnails is working fine for the widget version of the plug-in. My three columns automatically reduce to two appropriately sized on phone and ipad.

But I am also using the shortcode version, and with that one, the thumbnails go haywire on mobile devices, overlapping each other, and not positioning correctly, leaving gaps etc. The problem can be seen on this page http://www.owenwhitemanagement.com/1279-2/

Can you advise a fix for this?

Thanks
Chris

https://wordpress.org/plugins/youtube-channel-gallery/