Tnt Minecarts don't blow up at all

So basically i was playing with tnt and found a video about tnt minecart traps.

i tried one out and it didnt work i thought that was java edition only but that was not the case.

then i basically put an activator rail, put a tnt minecart and lit it up with a redstone torch under it and it didn't work.

 

that is all i have.