just went thru the same thing. had em in a container for almost 6 weeks. warmer the better. mine were at room tmep. but they did turn! either hang in there or move them to a warmer spot. and by the way my cham loved em!!!
basking site should be about 8" from the light. you may need a temp gun (about $15-20) to make sure your hitting the right temp. make sure you get vines that are different thicknesses. flukers makes a really thin one and a thicker one i have both. plus i have a ladder that people use in bird...
this is mine for my panther. theres no perfect set up but yours def needs more vines and plants. my bottom is bare. its elevated with holes drilled for draining. veileds will eat plants.leaves etc. so whatever you add has to be safe and will be munched on. ill have to get a few better pics. but...
i spray all around the enclosure. getting everything wet and dripping on the plants, he usually starts drinking the drops. i watch him. sometimes he approaches me and ill lightly mist him directly. but overall i dont go for him just all around him.
sorry to hear this news. my guess is it was a husbandry issue. some thing you may have missed. he may have been more stressed for longer than you thought. and yes enough stress for a long enough period can kill.
i found them slow and moved them in when they first came out,. then when they warmed up and flew toward the lights my guy took em out. My set up is a screen enclosure inside a green house. so if one got loose its in the greenhouse and easily caught and offered up
ia gree just converted mine to flies. my guy had a balst chasing thme this morning. he colored up and went to town. i didnt know he could move that fast lol.
panthers only need 50-70% average humidity. a constant 85 is to high. sounds like a RI. humidity is lower during the day (50-60) and spikes at night (60-70). this is one of the trickiest parts of chameleon care. keeping humidity levels and ventialtion at the same time.
just a qucik comment be slow and methodical in your movement. no quick movements. slow and steady dont lock eyes to much just do your thing and liek the others sais. linger hang around and he will settle. i agrre the falling thing is very unusual. patience is key