Hello Quectel Support,
I’m testing VoLTE on an EG25-G-GB module with a China Unicom SIM (LTE-only, no 2G/3G fallback available in my area). Module info: Revision: EG25GGBR07A09M2G_BETA0308_01.001.01.001 IMS is enabled but never registers: AT+QCFG=“ims” +QCFG: “ims”,1,0 MBN currently active: AT+QMBNCFG=“List” +QMBNCFG: “List”,13,1,1,“OpenMkt-Commercial-CU”,0x05011505,202012111 I found a nearly identical case reported for EG25-GC (also China Unicom, same MBN version 0x05011505): EG25-GC VoLTE/IMS not registering - request latest firmware and updated CU MBN In that case, Quectel support (fazrulredzuan) confirmed the issue was an outdated CU-VoLTE MBN and provided updated firmware containing MBN 0x05011508 or newer via email. Could you please provide: 1. The latest production firmware for EG25-G-GB with an updated CU-VoLTE MBN (0x05011508 or newer). 2. Confirmation on whether the GB variant supports mainland China VoLTE at all. This module was purchased second-hand for personal learning purposes, not through official channels, so I don’t have a project/PO reference — happy to provide any additional logs needed. Thank you!