I too have this problem. Please let me know whether your issue got resolved. If yes, how?
Recently brought LG Q6 from Amazon.
Problem is both the SIM not support my JIO VoLTE sim. At a time, only one SIM function VoLTE while other SIM does not function at all with showing message "emergency calls only". I tried both sim replacing to both slot one by one but no result Only one sim works. Also downloaded Jio Voice app and trying but no solution.
I brought this phone after checking info on LG website as well other phone site that it supports both the sim VoLTE network.
Pl suggest what should I check and do