Is your mobile phone has multi/dual SIM feature?
Is more than one SIM is active?
Is the default SIM is not configured?
If answer to all above question is 'YES'; then bluetooth calling will fail, as it can't decide which active SIM it needs t use to make the outgoing call.
My 2 cents... Hope it helps...
Cheers...
Great , its not only for this audio setup , even my Sony XAV had this issue. 6 months back my phone paired with bluetooth set of car , but I couldn't place call (The other person won't hear anything , as if Mic was disconnected), but when i tried with friend's phone, there wasn't an issue ( So ruled off mic issue , and thought phone's issue) , but quite recently unknowingly my phone was paired with car , and when a call came , i naturally , took call via bluetooth of car , but thing was the other person was able to hear via mic.
Now when you told this dual sim issue , i realised , thing was i had removed one sim from the phone , and kept in another set .
Thanks a lot for info.