Incorrect Lightbox Display

Hi!
I just noticed that in the Gallery Lightbox the attached code displays the controls incorrectly. Instead of appearing inside the lightbox, they show up at the bottom of the page after the content, as seen in the screenshot.

https://drive.google.com/file/d/17nN6USBRt_463eZoCbk-FDSBR5Jwssya/view?usp=sharing
https://drive.google.com/file/d/1GyYBrV2-GC1NEDhv6TgwNnmcxDl78Br6/view?usp=sharing

What can be done about this?

Thanks
Alex