I had to laugh today. I'm diving in Puerto Galera in the Philippines. The DM looked at my Hydros and said this was the second one he had seen. The boat captain chirped from the stern: "Yes that diver also had a Rolex and a Porsche!".
Seriously...I had a similar experience with mine rolling around then reduced my weights and problem was solved. I do not use a crotch strap but will add one for better stability at the surface.
Are you done with your trip yet??? Waiting for your report you promised