A couple of months back (I think it was with v63), Firefox changed the way to disable autoplay from setting
media.autoplay.enabled = false
media.autoplay.default = 1 # or 2 for ask
media.autoplay.allow-muted = false
This is all fine and good. But as of v66, this doesn't seem to work anymore, either - playback starts as soon as a page with a video in it gets loaded*. This occurs in a fresh profile with nothing changed but these settings.
Autoplay is still prevented when entering a url by hand/ reloading a page. The only cases that fail are clicking a link or being redirected (after a login, for example).
So my question is this: What is the current way to disable autoplay everywhere in Firefox v66?
*actually, only if it gets loaded in the foreground - background tabs don't start playback even upon receiving focus. Which isn't really the expected outcome from setting
media.block-autoplay-until-in-foreground = true (the default value) if autoplay were either allowed or disabled completely, either.
Edit: The precise version installed is
66.0+linuxmint1+tessa, on the off chance that it makes a difference.