T41p and YHS32 voice Quality

Dear support,

We have several T41p's with yhs32 headsets.
At factory defaults the headsets works perfect, manualy configured to 3CX.
After provisioning by 3CX-server, the voice quality for the reciever is to loud, it seems that the microphone is to sensitive.
The caller hears hisself back trough the headset speaker. The reciever gets a booming ear.

We have checked all setting with 3CX support, but all settings are good. In factory defaults there is a strange value in "headset_send =-32768".
The only good values wich can be input in the provisioning template are between 1 and 53.

Is this a bug in the Phone?

greets Remko