I am just spitballing here, but what if the normal key does have a computer chip, and that chip being in proximity enables the valet key to work? Have you read what the owner’s manual has to say about the valet key? When you think about it, when the valet key is normally used, the normal key should be somewhere not to far from the car?
If you haven’t already done so, read the owner’s manual from cover to cover. It might have something about this issue, and other things you should know.