Stress is certainly something that can affect their gut. It’s good he is still eating some at least. And producing normal looking poop. He may just not be entirely comfortable in his surroundings yet.

but he is loafing in one spot but is laying down and streching every so often.

Are you seeing him press his belly downward a bit when he’s stretching? That would be a classic sign of him having some intestingal discomfort. You could always try some simethicone (gas medication) to see if that helps improve his appetite.

He probably needs more time to adapt to the new environment. If you haven’t already, perhaps you could bring some familiar items over (like a blanket or something that he’s accustomed to at your old place) and put them in his area so he feels more comfortable with the familiar scent?

I’d recommend observing for a few more days as long as he’s still pooping, eating and drinking. It sounds like he’s stressed and bringing him to the vet may make it worse.