ios update referrer

Hi

We run a website that displays embedded videos. The videos are embedded via an iframe. The iframe only allows the referrer to be the website the video is being displayed on otherwise it throws a 403. The website is responsive. Since the latest IOS(9.3 and 9.3.1) updates if you refresh one on these pages the 403 gets thrown. This happens in safari and chrome.

In our tests users with an earlier version of IOS do not have the same problem.

Can anyone shed any light on why this might be happening?

Thanks

Matthew

iOS 9.3.1