Background video playback

As of the last update.. or so I believe.. video playback, more specific, buffering for videos stops when I close my screen or switch to another tab. Up until now I have had no problems with videos playing in the background while my phone was closed or I was in another application other than firefox. This recent update seems to have stopped this. When I close my phone the video WILL keep playing, but only up until the point that it had buffered to. I always use background mode. I have read about websites checking to see if your phone is closed and if it senses this, it will restrict background data. I don't know why websites have to do this... it's incredibly frustrating since this has worked in the past seamlessly. I love firefox and use it for all my browsing on all my devices but now I am using the Brave browser on my phone because I have no other current option to use background data. If brave can offer this simple function with the press of a button, why can't firefox?