As a follow up, neither FIFO example appears to enumerate.
Did you check in the Device Manager whether a new USB device is getting listed in there.
It might be enumerating but it may not be able to bind to the cyusb3.sys as probably it is not listed in the cyusb3.inf.
Try adding the VID and PID of SlaveFifoAsync example to the cyusb3.inf.
That was the problem. Unfortunately, I'm just coming up to speed on USB stuff, and would never have found that on my own. Thank you very much.