Lightbox gallery popup max size does not work for videos

Hi, I run the pro version of Huge IT Image Gallery and love it! I have just one minor problem: I have set the ligthbox popup max width to 1155px and max height to 900px and it works fine for my picture galleries but not for my video gallery where the popup width is only about 500px. The born resolution for these videos is 1200x720px. Hope you can help. Thanks in avance!

http://snabelsko.dk/animationer/

https://wordpress.org/plugins/gallery-images/