its because the normal loops all finish within one tick so you dont see it counting up.
you can achieve what you want by making it count up one number per tick, make an event like
compare scorecounter is less than score add 1 to scorecounter, this will fire every tick letting the counter go up 1 per tick.
you can pack this event in an inactive group, make an event "on level finished"->set gtoup active and in the group make the above descriped event followed by an "Else"->set group inactive (so it doestn check every tick if scorecounter is less than score)
hope this helps and wasnt to confusing!
if not i will try to explain it better tomorrow (its 1am here)