Using Collision without Update Age will prevent any particles from spawning. In Collision Query and Response DataInstance.Alive has a default value of false. If no other module sets DataInstance.Alive to true, this default value will be used, and cause all particles to be killed immediately.
Set DataInstance.Alive to true directly in the stack.
The emitter no longer has any particles. Re-enabling Update Age will start spawning particles again.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-88914 in the post.