Collapsed butt cheek. What are my options to make my cheeks look even again?

I have a Brazilian butt lift transferring fat from my Stomach to my butt. Years later about 9 I'm noticing one side moving downwards almost like I have two different butt cheek lines, similar to the double bubble look where the butt goes into my leg (the crease). I went to a few surgeons that said this area is to sensitive to lipo smooth. What are my options to make my cheeks look even again? The other side is fine but has lost some volume.