I've been using Zong VoLTE for about a month, but two days ago I noticed my phone was also activating Zong VoWiFi. However, VoWiFi only seems to work when I switch to a 2G/3G. After successfully connecting to VoWiFi, I can switch to a 4G network and VoWiFi continue to function. The problem arises when I'm not on WiFi. The network then reverts to 3G during calls. my phone appears to have difficulty switching between VoWiFi and VoLTE. Additionally, VoWiFi doesn't automatically activate when I connect to Wi-Fi while using VoLTE. Strangely, I need to manually re-enable 2G/3G networks for VoWiFi to work. I'm wondering if VoLTE and VoWiFi are still under development, causing this issue, or if it's specific to my phone. Should VoWiFi automatically activate on WiFi and seamlessly switch with VoLTE, or is this a common problem?