Hello! This is my first post and I wonder if someone could help me with this issue I have
I'll go through this quickly (keep in mind that in the Depth of field Effects layer there is another copy of the world layer which is tinted, but should affect only the dof)
Your world layer is set to be a guide layer, since you're overlaying things above it, the blend will only show on its own comp. In order to pass it along, you'll need to collapse pre-comp1 inside pre-comp3.
This will obviously break your 3d view, unless you duplicate the camera/lights and so on. What you're seeing in precomp-3 is exaclty what you'll see in pre-comp 1 if you turn the world layer off.