Firefox does not play html5 videos after sleep
Firefox does not play videos after windows 10 computer returns from sleep. In fact, if I visit video url such as this one https://www.w3schools.com/html/mov_bbb.mp4 directly it still does not play. I works fine until I put my computer to sleep. It is not connection problem because everything other than videos work. And with other browsers, videos also work. This problem started to happen recently for no good reason - no windows update or FF update that caused it. Does firefox play videos on it's own or does it depend on some external components? Tab icon shows me infinitely loading animation. However, when I open dev tools and network tab, it shows me that it's downloading 771kb, which is the correct size of that video. When I right click and choose view page source then I can also see the contents of mp4 file. So it looks like file itself is downloaded but there is some component that does not get notification.
Is there anyone who could explain how does video playing work in firefox internally?
Additional System Details
- User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0
I cant edit post so I have to post notes with this new reply: If I close and open firefox again, then it works fine. Even if I restart it in same profile. Also, when I start firefox with -no-remote argument and select some other profile, it works again.