Jumping in on this conversation because I am having the same issue. I also have two new Maximas I recently purchased less than a week ago. My first attached to my rock work immediately, I sat him high up on a semi flat area and he stuck. My other has jumped 4 or 5 times down to the sand bed. I'm trying to keep them as high as possible so I don't have to crank my lights up to high due to a few hammers, Zoas and a mushroom. I feel like no matter where I put it, it moves after a few hours. Do I continue to try new areas or purchase a flat rock and put him down on the sand? I don't have crazy lighting, two AI Prime 16HD's on a 36 gallon.