What video player is used on this site? In the past it may have been a man in the middle issue where security is a question. However when I tried to test this it did not have the issue. If it was Flash player it could be this: [https://bugzilla.mozilla.org/show_bug.cgi?id=863498] In order to file a new bug, unfortunately I was not able to reproduce this, but you may be able to report it here: bugzilla.mozilla.org and provide the device, the steps and the exact url that this is happening. Please also include the [about:support] information from the device.