BLUE TONGUE SKINKS

I have had my new northern bts for over 2 weeks now and he hasn't eaten at all in this time and has spent the whole time under the substrate (apart from the first few days in the humid hide).
I have read through other posts on here but their skinks would eat with no one around and then go hide again where mine isn't coming out at all (I moved one of our motion detection cameras in to the room so I know he's not even drinking when no one is there).
I don't want to dig him out of the substrate unless I have to. I saw one post where a reply said don't dig it out unless it's an emergency or it hasn't eaten in 2 weeks which mine hasn't.
It is 5 months old and the heating and humidity seem fine so I assume it's just scared from the move and the new environment.

Do I dig him out of the substrate? How long should I leave it alone before I try to make him eat?
Also if I do have to intervene is the best thing to just pick him up and put him next to his food or is there another method?

As a side question I'm offering him grain free cat food and vegetables at the moment (switching to dog food when he's older) and wondering how long you can leave it in the enclosure? I didn't want to leave it all day in case it goes bad but is there an upper limit?

Have you tried to move the food dish closure to where the skink is laying? What are your temps and humidity? I wouldn't leave canned cat food in the enclosure longer than an hour.

it could be because its colder and he's not getting enough heat, they rely on heat to function and without it their metabolism slows right down making them incapable of digesting food.
maybe you could try hotter foods like chicken ect
when one of my blueys wasn't eating i tried this and he loved it!
if heat isn't the problem (like you said)
you could try buying some love crickets or mealworms
they love them
hope this helps <3