- Corrected EFS + Persist (Download Here)
- Stock ROM (POTTER_NPN25.137-92_cid50_subsidy-DEFAULT_regulatory-DEFAULT_CFC.xml.zip) (I fixed mine with this, but any stock rom should work)
- Backup of your current EFS from TWRP (Check Step-2) (Important)
1. Extract the Fixed EFS + Fixed Persist in your TWRP folder.
2. Go to TWRP recovery >Backup & backup your EFS or (System+Data+Boot+EFS if you want to return to your current ROM after fixing VoLTE)
3.In TWRP Wipe (System+data+cache+Dalvik cache) & Flash Stock ROM (potter_NPNS25.137-92-4) and restore ONLY Fixed EFS before rebooting Phone (IMPORTANT)
you can just flash stock rom from bootloader and flash twrp and restore ONLY Fixed EFS before rebooting Phone (IMPORTANT)
4. Boot your phone for the first time & you will have ZERO IMEI don’t worry.
5. Reboot to TWRP recovery again and restore Fixed EFS + Fixed Persist and don’t reboot phone, reboot to twrp.
6. Make sure you rebooted to twrp from previous step and now restore your original EFS (The one you backup in STEP 2) & only then reboot phone.
Now your Volte Should Be fixed.
Now don’t ever flash stock rom again, and you are free to switching between custom roms but forget about coming back to stock, if you want to come back to stock rom, then use twrp flashable zip only. And yes after volte works do a backup !