I think it's another kind of exploration probe, somewhat innocently camouflaged as a rock... Something like Oumuamua, but this time more advanced and capable of collecting data of a different type and importance...
Surely these types of probes can travel faster by folding space-time when they are in areas of space where their creators know there are no civilizations that can detect them, and they adopt this type of "more normal" behavior when they approach inhabited planetary systems like ours... I say, just speculating!...