Is something wrong with my leopard gecko?

Well they are nocturnal so maybe he’s more active when you are asleep?? :-/

This has happened with my lizard (although it isn’t a gecko). I think that the main problem is that he is extremely bored and wants to get out of the cage and have some sort of interaction. I would suggest that you take him out of the cage every so often and interact with him. My lizard becomes more active when I do this.

Do you have a proper heat lamp?

What are you feeding Charlie?? :-/

Yes, take him to the vet as soon as possible.

This does sound like a serious problem. Make sure the heat in the cage is high enough. A lot of the time it is because they do not have enough heat to regulate their food or worse to make energy. Also try dusting his crickets with a food supplement (found at almost any local pet store). If that doesn’t help take him to a vet as soon as possible.