I had problems on my nothing phone 2 with volte, vonr(5g) switching. On 5g network and a voice call comes, it switches to volte which is 4g. Okay no problem there but when it switches back to 5g or vice versa, the volte or VoNR goes away, meaning calls and sms doesn’t work, data works flawlessly!
Flightmode or reboot was the only solution, or manually switching to 5g or 4g sometimes fixed it.
This mostly occurs when I’m using VoWifi, so I’ve disabled the VoWifi entirely. But still sometimes the same problem occurs.
After some digging and stuff, i finally found a way to fix this and it was simple!
Just adding some things to the APN settings!
I’m using a Jio sim so please make adjustments accordingly to your service provider!
The APN TYPE is what needs to be changed, by default it’s DEFAULT,SUPL,XCAP I’ve added some extras(like on the screenshot). I’ve Also changed the APN name and APN to jionet, previously was Jio 4g, idk if it’s necessary to change that but i changed it anyway.
For me, after saving these changes and rebooting, i have no more issues. Switches works flawlessly, no more call drops, or missed call alert from Jio, i even switched on the VoWifi and it’s works, No issues what so ever.
If you guys found this helpful, do let me know.