I checked this on both iOS (phone) and Android (tablet). The iOS screen is good. It says multiple devices are found, please select one, and there is a create button at the bottom.
On Android it has a big + at the top and says Create new device, it looks like a button but does not work. Really it wants you to select a device from the list. The actual button to create a new device is at the bottom.
Also, on the iOS screen it shows you how many rules are using a device, that would be helpful if people have multiple devices on accident.
Android (224)
iOS (260)
