How to enable Z2 D6503 VoLTE

Seems z2 supports volte but after enabling flag it does not show any options to enable it. I am on existenz Premium MM..
I have tried all available infos but no solution![emoji26]
Is it ROM related or what can be done to get VoLTE???

XDA
"Xcites: Develop: Achieve"

Xperia Z2 D6503 No service

Hi everyone,

my Z2 was updated to marshmallow then lost the baseband, after several times trying to restore it, it didn't work, until earlier, i reinstalled 6.0.1 stock wiping every thing, the phone starts telling there's no sim (the sim is inside), and after 4 or 6 minutes, the sim icon turn pressent but empty, the baseband come come again, the imei come again, but it tell No service
This phone was working okay, the sim card was 100% functional and unlocked, could he been relocked again ? what suggestion do you guys have.

Thank you all !