I replied to the other thread you made with info.

From the carapace shot it looks like it might be a male.. but it was blurry & since it is young the vent can easily shift & change the suspected sex.

Fill in the gaps where the big rocks met with the side of the container. He can easily fall in there & drown.

the water looks shallow. is he having problems swimming? it should be deeper. He should be in a 10-20gal long tank that is about 50% full with a spot to get out. If he is out of the water all of the time or a lot he might be sick. Snappers don't need to bask & it's rare they do. Younger ones do it more often, but even then, they stick to the water.