VoLTE

[woodmj]

Just noticed although I have VoLTE enabled in my phone settings & O2 account my phone switches to 3G for calls. I wonder why that would be?

I'm a pay monthly customer using a Galaxy S9 & the latest O2 firmware.

[MI5]

VoLTE calls are not available everywhere, so if it's not enabled in your area, it won't work yet.
http://status.o2.co.uk/

[woodmj]

The checker indicates I should have a good 4G calling service in my area.

[MI5]

Does wifi calling work for you?

[woodmj]

Nope.

[MI5]

You've got an issue with setup then. Try removing the wifi/4g calling option from your MyO2 and reapply it after 24 hours.
If it still doesn't work after that, you'll need to find someone in customer services who can help you.

[woodmj]

Well that's odd.

I had the services disabled & re-enabled & now the phone doesn't drop the 4G icon during calls but doesn't display the VoLTE icon suggesting it's using VoLTE? & I think I test WiFi calling is working by enabling Flight Mode & just enabling WiFi (so the cellular radio is off) & calls are made if my router's WiFi is on but not if off but the WiFi calling icon is not displayed during the call.

[MI5]

On my OP6 I only get the icons if I pull down the notification screen, not on the top bar itself.
Sounds like you're working OK now anyways......

[woodmj]

It seems to only want to use WiFi calling if there's no cellular signal. Shouldn't that be the other way around?

[MI5]

Not sure on Samsung but I have the option to set WiFi priority or cellular priority. Check your settings.