You changed his familiar turf...chams don't like change. He isn't going to die because you added a stick. It will take him a while to decide it isn't going to be a threat, but he will. Now if he can't reach his basking area, his food, or water, or the stick is too big for him to grip safely I would be a little more concerned, but most likely he will adjust. Possibly add something that gives him a path over or around it as well?
just wait and he will get used to it.
My chams don't mind when I add things. In fact I added a couple of vines to Rupert's cage today, and he spent hours walking around and checking for comfy spots.