WHY Main IVR will keep play even if a press a digit to go next ivr

I have main ivr, its intro, for mangement press 1, for development press 2
if i press 1 (which forwards to next ivr) it will not play the ivr untill the main ivr is played/

when i hear for instance for mangement press 1, and i press 1 right away, it wont go, only after all the ivr finishes