Just found this post: Matterport WebVR Support for the Oculus Rift and HTC Vive

"As a platform, WebVR is new. WebVR for PC is extremely new. While we here at Matterport have done our best to minimize issues, there will be bugs. Sadly, many of these bugs we will not be able to address as they might be issues with Firefox, Oculus, Steam, or other settings/drivers on the end-user’s PC. You may need to do a fair amount of troubleshooting to get WebVR support working for your Rift or Vive ..."