Full Screen on latest Iphone 11 is grayed out

On mobile, the latest version if iphone 11 the ‘full screen’ icon at the bottom is grayed out and cannot be enlarged. This full screen icon DOES work on my older samsung galaxy s8 plus but not on the latest version of iphone.

I’m assuming this is a bug so thought i’d pass this along. Will you review this and possibly release a fix for it if you know what is the reason?

or is this something within the latest iphone 11 browser that forbids full screen for some reason?

The page I need help with: [log in to see the link]