[Jakov_the_Jakovasaur]

im not sure if this is the case with more recent npc-server versions but it certainly was the case before, an npc needs a setshape() to be found by findareanpcs();

your check should still be improved though, currently it is attempting a loop only to return once it finds any npc, which could be the case for a random non-blocking npc, there should be a check within the loop to determine if the npc is either blocking or is a dirthole

it could also be very unsmooth to be triggering like that in order to play a sound especially given a high latency, if you do these checks on clientside first you can have the sound play in real time (and even put it in a gani for others to see), then you can do the checks again on serverside as a matter of preventing duplication or for security