Due to restrictions enforced by Apple, the VR/360 content needs to be hosted on the exact same domain than the website.
To be recognized as the same domain, it is required that the protocol (e.g. HTTPS), all subdomains as well as the port number matches. If this is not the case, your iOS device will not show the video but will play the sound. Please note that this restriction applies to VR/360 content only.