Hello,
Thanks for using our theme.
http://prntscr.com/10wufl0 – Is Product Gallery Slider enabled in Theme Options > WooCommerce > Single product page > Single product layout?
http://prntscr.com/10wudfz – try to activate Product Gallery Slider Auto-Height via Theme Options.
Also, I would recommend using a graphics editor and prepare images (make them the same size) before uploading them to your media gallery.
Do you want to use Single Product Builder or one of the default layouts? Provide URL, temporary wp-admin, and FTP access, we will check the situation more deeply.
Regards















