Lightbox does not display on IOS devices.

Hello,

I have recently noticed that when I click on the customize button on my own android device everything works properly. However, when doing it on someone else's IOS device it does not display. The strange thing about it is that the buttons are actually on the screen and clickable but it just does not display anything visually. 

Do you have any CSS code /JS code I can try out to make the lightbox display on IOS devices,

Thanks.