[Q] GALAXY Note 4 - SM-N910U HD Voice

Hi,
my device : PDA N910UXXU1AOC3
CSC N910UZZH1AOC3

connected to Orange israel that supports the HD voice - but the device doesn't get it.

i have an Iphone 6 with same company and HD voice works with iphone 5 and above in the same cellular company.

what can i do?