Hi John,
There are a variety of things that could be wrong. How long have you had him? Sometimes reptiles need to aclimate to their new home and surroundings, and it could take a week or so, depending on the individual. You don't want to handle him until he's aclimated. You want him to feel he's safe and secure and it's his territory.
Not sure if you have kids handling him but you want to limit it to 5 minutes maybe every other day? And talk to her about safe handling, sitting down while holding so he doesn't fall from a height, and not taking him out with friends around because the friends may not show it respect.
Also, if his tank is near the floor and dogs, cat's or birds can be seen, that could cause stress. Concerning his behavior, you have the temps with one end hot, and the other end cool so he can thermoregulate? Is he sleeping in a dark cool corner or is he on his basking site constantly?
Sometime's they go into brumation if allowed to get cold too often. That's probably not it if your right and consistance with your temps. Also not good for a new beardie because if he's got parasites it could lower his tolerances and possibly be fatal.
You mentioned, he was eating, but didn't say what. If you could tell me what he's eaten daily in the past week? Has he eliminated and is he eliminating daily? When he eliminates is it loose and runny or hard and chalky? Looking at the feces can tell you if there's anything wrong with his diet or if he's sick. If it's runny, it may mean he has parasites and needs to see a vet. Put a sample in a baggie in the fridge and bring it to your local exotic vet. They may want to see him.
If it's hard with little to no white (urates), it could mean he's dehydrated and you need to get him drinking, maybe soak him in a chest height bath for 20 minutes once a week? Giving him fresh veggies like collard greens, kale, dandelion greens, zuchini, carrots, etc. daily will help keep him hydrated.
Dehydration can cause him to sleep a lot. He should have fatty pads on his head, tail base should be full, skin should not be tented and wrinkled. Those are signs of dehydration or emaciation.
Giving him a varied diet of bugs and veggies, and dragon pellets, dusting bugs with vitamin powder once a week for adults, should keep him healthy. Last thought I have is, if he hasn't eliminated at all, it's possible he's impacted, either from dehydration, or if your giving him lot's of bugs with no veggies, and their exoskeletons are not passing thru.
Giving him a warm soak for about 20minutes, massage his belly gently and he may eliminate there.
Hope that helps!
I