I found a solution for this problem. Just add extra pressure point to the bottom case. See image. Red marked areas needs to be have extra tape or something that press the speakers down. After that the problem is gone. You have again the great bass :D. I also taped my speaker with a thin double sided tape.
I have also this problem, but when I connect to external display, the display works again and I can use it for while and it happens again. Black screen.