hi

it may just be the case that your new geckos will take a while to settle. My gecko goes through spells of being quite active for a few days and then for the next few days she will spend a lot of time in her hide. She is normally a bit quiter when she is coming up to shed.

As for the hunting, geckos will stalk crickets but more often then not they are lazy hunters and will not stalk something until it is like 1cm away from its mouth!!!

All there is to suggest it check temps and humdiity, which I am sure will be fine.
I also dust my crickets with a gecko formula to keep them healthy. Geckos may get their calcuim in the wild from licking sand as where they come from they live on rocky outcrops, mixed with soil and sand.