My MacBook Pro Retina is not seen by other's airdrop on Yosemite

Hello! I'll really appreciate some help here...

I can see everybody on my airdrop, and send files to everybody. But no one can see my mac on airdrop, neither send me files. This happens from macs and iOS devices, I can send files to them but they just don't see me...

What I've done:

Checked my Firewall (is off)

Changed like 30 times from "discoverable by: contacts only" to "everyone" to "no one" and back...

Bluetooth and wifi on

Again, I can send files, but no one see me... But, and this is the crazy part of the issue... sometimes (with the exact same configuration) i have been seen by the same devices that doesn't see me now!!!! Maybe in a few days the devices may see me again ... this is crazy...!

Does anyone knows what to do ?