It's the Privilege Aluxes. It was originally classified as a 5* and I had it booked but was just notified by HOTWIRE that they've now classified Privilege Aluxes as a 3.5*.
UPDATE!!! I was just informed by Hotwire that they have downgraded the 5* Privilege Aluxes to a 3.5* and are giving me a refund. so there is no longer a 5* on Islas Mujeres, the Privilege is now a 3.5*