With my phone on, if I go to the Bluetooth page in Settings, it will display what I have paired, and it will go into discovery mode and I can see "Other Devices" and the spinning wheel. That is because it is in Discovery mode. Just close out of that page and it should be fine. It doesn't stay that way for long. Again, with AirDrop, you do not pair the device, you just need to have Bluetooth turned on, not paired. The only way it will discover the other devices is if they are in discovery/pairing mode, and they support a Bluetooth profile that is supported on the phone.