Opening links on iPhone cuts off the bottom part of the prototype

We have a footer with the main navigation of the designed app and this needs to have a fixed position while scrolling. But when opening the link on an iOS device the footer is hidden at the bottom and isn't accessible.

We tested it on 4 iPhones (2x iPhone X, a 7, and an 😎 and tested on Chrome and Safari, same results.

It worked fine on the Android device we tested with.

Also tested multiple links from different projects, always the same issue: Fixed objects are hidden at the bottom of the screen.