airdrop failed from mac yosemite to iPhone 6

I have iPhone 6 and Mac - Yosemite and I can't find why the airdrop from Mac to iPhone is not working (only this way)? I tried to send files from iPhone to mac by airdrop - everything was ok, but from mac to iPhone - I have found my phone, then waiting long time for connection and then it failed 😟 Also from time to time I can't even find my iPhone in Finder- Airdrop ... I set airdrop allowed for ALL, I reset my privacy settings, I really don't know what else to do. I tried also to send file from my mac to my boyfriend's phone (also iPhone 6) and everything was working. Any ideas?