This can be normal. Each chameleon is different. The normal practice is to place the female into the male's enclosure. But I have one male that prefers to be placed in the female's enclosure. He is just too territorial to allow her into his. I have another adult male chameleon who was afraid of breeding for a while, but then became interested a couple of months later. I would occasionally show him the female. Outside his cage, and then at the opening of his cage with the door open.
For another pair, the male takes a long time to warm up. So, I have to leave the female in there for quite some time before he will approach her. Be careful about leaving breeding chams alone, however. Terrible things can happen if one or the other decides they aren't keen on the notion of breeding. Also, things can happen accidentally as well, and you may need to be there to intervene.
So, some things you can try are:
Leave them together for a good length of time. This allows his hormones to kick in. Some chams are always ready, others take a while for the brain to trigger the hormones.
Or try putting him in her cage.
Or introduce them to each other slowly and let it develop over a few weeks' time.
