Your problem might be dehydration. I spray my jackson about 4-5 times a day. Two times just isn't enough, especially if he isn't drinking directly from the spray. Jackson's require a lot of humidity so try to keep it up by spraying atleast every hour to an hour and a half for about 45 sec. at a time. You don't have to give him a direct spray, just mist the leaves and anything else in his surrounding environment. I don't know if yours does this, but if i get the bottle close to him and lightly drizzle water on him, he drinks right out of the bottle. (a very good way to keep him hydrated.) Another thing you can do is put your jackson in a ficus tree and stand it in the shower. Make sure the spray from the shower is very light and doesn't hit the tree directly. Just make it so the water drips down the tree lightly kind of like a light rain. The water shouldn't be any hotter than luke-warm. My Jackson loves it! Hope I could help you.
~ Dan