Axies can become very stressed out very easily....being shifted from one aquarium to another will induce extreme stress.
Ideally an Axie doesn't need heat or light...other than basic natural daylight. Without eyelids any source of light is painful to them and should be avoided. The stress levels can sometimes affect the metabolism, which is very slow normally (feeding once or twice a week is average normally), so leave him unfed for a few days.
He may have impaction. if he has over eaten or eaten something like a plastic plant weight or a stone (anything they can get into their mouth, they will get into their mouth). If he is impacted you will need a large sandwich box with water from the aquarium in it, scoop him up in the box (do not handle him in any way since it damages him and makes him prone to bacterial issues), put the lid on the sandwich box and place in the bottom of your fridge for 5-7 days. The lowered temperature will allow him to pass whatever is impacting without tearing his gut or anus.
However, since it has only been a week since he was moved, I am fairly sure its simply very stressed...his gill feathers are also not healthy...water chemistry is likely to be a little off and high stress levels make a very unhappy Axie who turns down or spits out food.
Let him rest in darkness (big towel or two over the entire aquarium, totaly darkness) for a few days, let him calm down and get used to his new home slowly. Just as with fish when they move home, they need time to adjust to the new surroundings and water, so do Axies....more so with Axies due to absorbing everything through the skin and any issue with water chemistry will upset them.
(I owned a big male Axie for almost 4 years and upgraded him a couple times on aquarium size and went through this sort of thing...and the blighter took a weight off an artificial plant and had to be refrigerated for a week)
