BC127-HD problem with BT_VOL_CONFIG

Hi guys!
I’m experiencing some problems with the BT_VOL_CONFIG, more specific with the a2dp volume steps, right now I have it set to 10 (which is the default), but it still changes depending on which device I have connected to the module. For example for an Iphone I have 17 steps, and for a Samsung I have 16.
Am I missing something on the configuration, or this configuration is not actually to set a rigid number of steps for the A2DP?

This is my configuration at the moment:
AUDIO=1 1
AUDIO_ANALOG=0 0 0 OFF
AUDIO_DIGITAL=0 48000 64 100200 OFF
AUTOCONN=1
AUTO_DATA=OFF OFF
BALANCE=100 100
BATT_CONFIG=ON 145 3700 1500 150
BC_SMART_CONFIG=68E3 28F0 89F7 D93C
BEACON_DATA=0 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF 04 D2 16 2E EE
BLE_CONFIG=0 OFF 80 OFF
BLE_CONN_PARAMS=128 12 24 40 0 400 100 400 400 64 400 400
BT_STATE_CONFIG=1 0
BT_VOL_CONFIG=9 50 10 1
CLASS_1=OFF
CMD_TO=3
COD=240404
CODEC=8 OFF
DEEP_SLEEP=ON
DEVICE_ID=0001 0002 0003 0004 0005 0006 0007 0008
ENABLE_BATT_IND=ON
ENABLE_LED=OFF
ENABLE_SPP_SNIFF=OFF 0 0 0 0 0
GPIO_CONFIG=ON 0
HFP_CONFIG=OFF ON OFF OFF OFF OFF
HIGH_SPEED=OFF OFF
LOCAL_ADDR=20FABB1B33DB 20FABB1B33DB
MAX_REC=2
MM=OFF OFF 0 OFF OFF OFF OFF OFF
MUSIC_META_DATA=OFF
MUSIC_OLD_AVRCP=OFF
NAME=Neo Auricles
NAME_SHORT=NEO
PIN=0000
PROFILES=3 0 3 0 3 3 0 0 0 0 2 0
REMOTE_ADDR=000000000000
SPP_UUID=00 00 11 01 00 00 10 00 80 00 00 80 5F 9B 34 FB
SSP_CAPS=3
TWS_CONFIG=OFF 1 2
UART_CONFIG=9600 OFF 0
USB_HOST=OFF
VREG_ROLE=1