The modem seems to be missing mbn. Please send me the “Commercial-LGU” mbn file to use VoLTE.
ATI
Quectel
EP06
Revision: EP06ELAR04A05M4G
AT+QMBNCFG=“List”
+QMBNCFG: “List”,0,1,1,“ROW_Generic_3GPP”,0x06010821,201901151
+QMBNCFG: “List”,1,0,0,“Telstra-Commercial_VoLTE”,0x06800118,202104151
+QMBNCFG: “List”,2,0,0,“Volte_OpenMkt-Commercial-CMCC”,0x06012064,202107271
+QMBNCFG: “List”,3,0,0,“OpenMkt-Commercial-CU”,0x06011510,202109061
+QMBNCFG: “List”,4,0,0,“TW_Mobile-Commercial_VoLTE”,0x06800201,201712042
+QMBNCFG: “List”,5,0,0,“Commercial-DT-VOLTE”,0x06011F25,202008051
+QMBNCFG: “List”,6,0,0,“Commercial-KT”,0x0601270B,202102251
+QMBNCFG: “List”,7,0,0,“Commercial-Reliance”,0x06011B34,201904021