Okay I think I know the solution to this and it's really easy and as I am writing this, I have to do it everytime to work. The solution is... wait for it...
turn BT on/off.
I posted recently that I had BT problems and tried everything I know and still not working. The first time it happen is annoying like I read a lot of people complain here how when they connect to BT, the wifi disconnects. Now, when I play youtube video it is either buffering non stop or playing video with no audio. So I tried to turn BT on/off. It works. But I find I have to do it everytime now.
Oh I have to say my BT problem started after I connect my phone BT while it's connected to my laptop BT. It used to not be a problem as long as I turn off my phone BT after I am done with it.
Also in my case, my echo's BT can't be connected to both phone and laptop at the same time.