When an ad plays before the video, the 16x speed continues on to the video (and in some cases also mutes it). To fix this you have to go into playback speed settings, click a slower speed, then go back up to normal speed. To fix the muting problem you have to mute the video and then unmute it. The whole procces is very annoying. From what I can see, many people are struggling with this problem. It needs fixing ASAP.