Is there any reason why you did not enable VoLTE using the toggle in the OS Settings under network & internet? On some devices it's called 4G Calling.

    Neoniq it wasn't there.

    Did you speak with your mobile carrier about why that is?

        treequell it shows VoLTE enabled in settings in their app. I didn't speak with them.

            Neoniq There are some tips here for enabling VoLTE: https://grapheneos.org/usage#carrier-functionality

            Neoniq Requirements: Shizuku

            It is recommended to avoid using Shizuku since it requires ADB to be enabled, which greatly increases attack surface on your device. Based on my understanding, enabling ADB allows all sorts of processes to run on your device which are intended for development purposes only. Therefore ADB should be avoided on a daily driver in the interests of security.

                  See the reply in the linked GitHub issue from Upstate1618.

                  ADB provides a massive amount of access even on a production (user) build, and on a userdebug build it even provides root access. ADB without the network feature relies on requiring physical access in addition to key-based authentication which expires. Network ADB support is actually quite problematic and is a malware persistence method reducing the security provided by verified boot substantially. We plan to do something about it, but we aren't quite sure exactly what we want to do yet.

                    treequell it does not require Shizuku/adb running all the time. Only once for VoLTE enabling. Then reboot and you can remove Shizuku and VoLTE enabling app altogether.

                      5 months later

                      I had a problem with the Shizuku solution on my Pixel 7. I installed it, enabled VoLTE toggle on settings (which was not there before shizuku), but after a reboot my phone was getting INSANELY HOT, I realized that in order to solve that I had to open Shizuku after every reboot (even if the VoLTE toggle was still ON) and disable it and the enable it (doesn’t worked every time). I ended up uninstalling Shizuku and disabling VoLTE since GrapheneOS get updates (and reboots) almost every week (sometimes even twice a week).