im having the same problem. i only have this problem between mac and iphone/ ipad. mac wont detect my phone/ipad. same goes for phone / ipad, they wont detect the mac. however i can successfully transfer between iphone and ipad without any issue at 0% failure rate.
Im using MBP 15" Mid 2015, iPhone 6s, iPad air 2.
what i have tried :
1. turn on and off bluetooth and wifi
2. set airdrop to everyone
3. reset my router
4. sign in and out from icloud
5. turn on and off icloud drive
6. restart both mac and iphone/ipad.
7. turn off firewall
8. delete the /Library/Preferences/com.apple.Bluetooth.plist
tried all of the above but still the airdrop wont detect my device. however the handoff is working great. only airdrop is not working.