@Julie750, as @Marzena4 has said, it is possible that two people are promoting the property to get more bookings.
I have also heard stories where someone will steal the photos and description of a popular property to make a fake listing. The original host is innocent and often unaware of this. I do not know if this is the case, but perhaps you can contact both hosts and tell them both about the duplicate listings.
How they respond might give you more information about what is going on.