Hello,
Unfortunately not all newly hatched chameleons make it. The hatch rate declines even more when you get into retained clutches.
First off I would suggest letting them be able to cool down. A constant 80 day and night is not good. Daytime you should try to achieve temps ranging from 70 to 78 and a basking site of around 80 or a little higher. Night time they should be able to get down to at least 70 degrees. A cooling period at night is detrimental for all chameleons. Some require greater temp drops than others but it is really important.
There are a few things you can do with the sickly ones. Separate them all into their own small enclosures. Can be 5 quart plastic bins, small fish bowls etc. Nothing too big. I do and will not baby any new hatchling that is having trouble. If they perk up on their own with correct husbandry, so be it. If they dont show any signs of getting better I euthanize them or feed them off to another larger chameleon. Might sound harsh but if they are going to die you might as well get some use out of them and nutrition for another animal is on the top of that list. There is no sense in letting them sleep all day and eventually dieing from starvation.
You do need to have temperature fluctuation or I dont think any of them will thrive.