BC127 - HFP/AGHFP configuration

I am using two BC127 : “board-A” is the gateway (AGHFP) and “board-A” is connected to it using HFP link.
I am playing with AT commands :

  1. from board-A to board-B : I can send command manually and got no problem.
  2. from board-B to board-A : first command I send has no problem, but after that every commands takes exactly 5 sec to reach the AG. Is there any configuration I should use ?