Just reread the size, I wouldn’t expect hump growth till 4-6 inches.
As it grows it will get some confidence and rise up the ranks. Just give it time and a hump should come in.
The hump may not even grow if it's not looking to dominate or convince female cichlids in the tank to mate. I had a green terror that was happy to be at the bottom of the cichlid hierarchy because it couldn't match the aggressiveness of the other cichlids.