Dark matter is not a thing, it’s an observation, a phenomenon that was poorly named. There’s so much evidence under the name “[d]ark matter” that we can’t discount it as a real phenomenon. We just don’t have a strong evidence for a single dark matter theory (theory in the scientific sense of the word, not the colloquial one).
They don’t “communicate” faster than light, the wave function itself is non-local and collapses non-locally.