Might have broken teh switch on teh top board, very common.
Because you push it in, and dont reach it, you push harder, then it works, so you think its a delay.
this could also be a loose grip frame thats slipped back abit there is a small amount of play -loosen the frame bolts and see if it will sit any further forward (i.e mm's)
no the trigger stays in - there are two small pins that go through the trigger switch and the frame just use a small allen key or something to poke them out from one side - dont touch the larger trigger swivel pin on the frame then just ease the board out .
BTW the two small pins are covered by the grips when you put them back on yoiu know the ones yeh?