For some reason, AirDrop has been flaky for me (used between my iPhone 6 Plus and my late 2014 Mac Mini). Sometimes, I have to wait wait wait for my iPhone to find my Mac. It used to work in how far is Tampa from Miami 1800 yen to usd an instant. Now, there's always a wait. I haven't been able to figure out idea why. So, I can't help you, but at least you know you're not the only one having issues with AirDrop.