during the last days talking with some developers of blueZ and pulseaudio, I figured out the problem could be PA. In fact someone told me that pulseaudio is not fully compatible with blueZ5, I mean it doesn't provide a way to register a HandsFree Audio Agent to manage the bluetooth HFP communication, so the chain blueZ5 -> oFono -> pulseaudio cannot work well!
I'm trying to talk with some oFono developers to understand if my previous conclusion is correct or not, but I wasn't very lucky lately.
As far as you know are there a way to solve that problem or if exist an anofficial version of PA that provide the support to blueZ5, oFono and so for bluetooth HFP?
Thank you very much for your reply.