You said..."Gut loaded with spinach most often"... Spinach binds calcium and should not be used verynoften I'd at all. Dandelion greens, kale, collards, squash, zucchini, sweet red pepper, sweet potato are better choices.
Younsaid..."We also use a calcium fortified gut loader for them. He eats about every other day"...what specific gutloaded do you use?
Younsaid..." we use rep-cal calcium with vitamin d and also rep cal herptivite multivitamin"...how often for each? No phos free calcium powder at all?
I don't like the shape of the belly...it looks bloated but somewhat flattened on the bottom. Does he hold his belly up,off the branches at all or mostly rest on them?
Any possibility he's been eating fake plant leaves? Is he still pooping?
I would get rid of the fake plants and use real non toxic ones well washed both sides of the leaves.
Does he have trouble holding on to the wood pieces in the cage...they're at a steep angle and maybe slippery. couldmhe have fallen?
I really think you need to get him to a very good chameleon vet ASAP.