i was readying the original question and comments about the ball sticking to the top wall, the solutions i read were inadequate in my opinion…
when i discovered this problem i just happened to look at the info section of the box collider and realised there was no bounce, i then attached the bounce material we made to the 3 walls and bingo, everything worked like a charm…
just felt the need to mention it and hopefully one day the video will be addressed with a side-note or something.
oh i almost forgot, i had to reduce the friction of the bounce material to zero so it would actually bounce (rebound) correctly or the top wall will not rebound at the angle of attack and side walls will actually slow the ball down because of the friction…
the block(s) also need the bounce material applied or the ball will just basically die… which led to the great idea of having different bounce materials for it i wanted to for example make a block slow down the ball or speed it up etc 
there may be a more complicated way to solve this problem, but this is how i solved it.