Hi Chris!
That sounds a lot like the exo terra glass vivarium a that have front vents to help with airflow. I wouldn't worry as long as they are clear from debris. My advice would be to be careful with the dropper! In my enclosure (also glass) water will build up if the dropper is on for more...
Might be puberty. I know it sounds odd but Chameleons get hormonal too!
My Veiled also enjoys having drastic mood changes. He will want to come right out some days and others he will hiss when I clean his poop. I named him Mr Grumpy for a reason.