I using Firefox Nightly 67. And I like the fact that on the home page of a youtube channle the video is not preload and auto played. But when you click on a video link the video... does not auto play but it does preload I wish it did not thought. If the opt. did work... if would good if the all youtube videos did not preload and auto play. Because I'm not always watching youtube videos sometimes I'm reading comments,and or going to another youtube from the video that I'm on.