I have the same problem. I do not know what is causing it. but I have also noticed that the settings button that is supposed to occupy the center space on the playback bar is missing.
Posts made by tranceemerson
RE: Opera 52 Problem with 360 video player / Oculus RiftOpera for Windows
VR 360 player struggles to get 10 frames a second.Opera for Windows
I don't know why but whenever I use the VR 360 player the frame-rate is really laggy, and I can not playback at the recorded framerate. also there appears to be a settings button missing from the VR player's control bar.