Lightbox gallery for Global Gallery plugin on mobile

I’m running into a small issue as far as mobile is concerned.

When viewing the gallery in mobile, the lightbox remains at the top of the page. Is there a way for the lightbox to popup relative to the image clicked?

I asked the plugin author for a fix as well. His response:

Checking on desktop browser resized, everything is ok. While on mobile your website has a strange behavior:

“engagement rings” banner stays on top and partially hidden. Gallery images are on two columns and, also them, partially hidden. Finally, lightbox wrapper is locked on top of the page and doesn’t scroll.

I’m almost sure you have some graphical glitch on mobile view. Looking at the code everything seems ok, then should be caused by some wrong CSS setting.

I tried looking for a CSS issue with no luck.

Any ideas how to make this work?