So, I am using r14 and r13. (Tried it on both). When I put a camera into a circle and try to rotate or move the circle it doesn't work. Someone told me it might be regarding the tools selected or something. I do not know.
If you're trying to make the camera fallow a spline, or go in a circle. you have to add the "Align to spline" expression. Then use the Target tag if you wish to have it focus on one object. Here's a youtube video of what I said