Mine usually lick the leaves that have water dropplets on them. I've seen some of mine do it, some I've never seen drink.
If you think they're not drinking at all, take a look at a fresh poop. It should have a brown log thing and a white goopy part. The goopy part should be white. If it's yellow or orange, it indicates dehydration.
Iv seen every chameleon iv had drink, i have a fountain you know, but iv also seen them drink from leaves, most of the time though i walk in on them drinking and they don't usually start drinking it in front of me.
MOJO try a long misting session.
I mean fill up you hand mister with about 8oz of warm water, and give you chameleon a long soak.
When I first start misting your chameleon may freak out, but dont worry.
Try to get the mist to spray onto their head.
The water driping down their head to their mout will trigger a drinking response.
That being said you dont want to use a heavy droplet "trigger type" sprayer.
Make sure it is a good fine mist.
This is what I use to use.
I have found that my veiled loves to drink at night. If I spray her during the day she will hiss and run away no matter how long I mist her for. But if I spray her at night, she loves it. She also drinks a ton from her dripper at night. I just wait until the light turns off and then I spray her and turn on her dripper. I'm sure this would work before the light comes on too, but I am not a morning person.
My chameleon used to drink in front of me, but he doesn't all the time now. He used to drink from a dripper but he won't now. Sometimes he runs away from the water but it's tough luck for him, I keep misting anyway. Sometimes he extends his tongue to catch water like he would crickets, although to me that seems less efficient than just drinking from the leaves like he used to. I don't know why he has developed this latest behavior, but he has been kind of weird all-around. One thing I have learned is that they will wait for you to leave to do what they need to if they don't want to do it in front of you.