Why could it happen that an object that receives the instruction "my.passable=on;" inside a while loop, doesn't become passable in engine running?

while(my!=null)
{
my.passable=on;

my.alpha=100;
var targ[3];
vec_set(temp, my.x);
temp.z -= 900;
c_trace (my.x,temp,IGNORE_ME|IGNORE_MODELS|IGNORE_SPRITES|IGNORE_YOU);
while(vec_dist(my.x,targ)>5)
{
c_move(me,nullvector,vector(0,0,-10*time_step),ignore_you|ignore_sprites);
if(my.roll<90)||(my.roll>180){my.roll+=10*time;}
wait(1);
}
wait(1);
}

Maybe you didnt set a my pointer?

Try removing 'ignore_models' if its a model entity.

Nope, tried that and it didn't work.

Add ignore_passable in your c_move mode list.
Btw, better set the passable to your targets
instead of the player.

I got it, the passable flag updated and contradicted my wishes too fast for me to notice.