Their is a new option now available in 9.6.2/3 on Sim Cards or Network i.e Dual VoLTE .. Just enable it n it'll work for Vodafone n all Idea users .. remember that Dual 4G option Also be enabled which was rollout on 9.5
Unfortunately, I don't see an option 'Dual VoLTE' in the settings. Only have the Dual 4G option.
Below settings are enabled:
VoLTE Enabled : Enabled
Dual 4G : Enabled
Use mobile Data during VoLTE calls on the secondary SIM : Enabled
Btw, are you referring to Note 5 or Note 5 Pro? I'm using Note 5 Pro.
Thanks in advance.