Post-processing components do not blend

Dear forum,

I have an actor with an unbound post-processing component that can generate a space warp effect centered around the actor. The problem is that when several actors of such type are spawned in sequence at runtime, the post-processing effect of the actors spawned earlier immediately disappears when the actors spawned later begin to take effect. I had expected a blend behavior rather than complete override. What seems to be the problem? Can multiple instances of post-processing components blend with one another?