Why i cant spawn a object in random place?

Sorry for my bad english, i’m from Russia.
i Writing a simple game for Android on GDevelop, and i cant do “Create a object WoodenBox in 0;Random(1000)-500”, object spawns always in same place (in 0;100, because earlier i use this coordinates for test a spawn and physics)

And one more question - how to do a 2 physics layers? i have fireballs, flying up on physics, and i have the boxes,I need to box is not faced with fireballs (i need to create a another basic layer, i think, but i don’t know how to do this)

Thanks.

It should work, you probably made a mistake.