sindi wrote:I changed webm to TRUE and restarted and still have only 360p/auto.
Can I add the missing lines in about:config ?
No, adding them will not do anything. It is strongly recommended that you reset the media prefs to their default values, particularly the one for WebM.
Firefox and SeaMonkey's media backends are vastly different than Pale Moon's currently is. Just because something "works in Firefox" does not mean it will in Pale Moon (and in fact in many cases can make things worse).
@sindi do you have FFmpeg (and specifically the libavcodec component) installed? If so, what version is it?