Wifi calling Xperia 1 not working

[ATNeuromonkey]

I recently got the Xperia 1 from O2 and for a couple of days the WiFi calling was working now it is not. I have done many restarts of the phone, checked the firmware, but have had no luck getting it back i.e. there is no options in the networks settings available for it anymore. Can anyone help?

[Xperiafan]

Having the same issue any updates?

[Foddersin]

This will probably come and go until they resolve whatever issue it is they have with the device or until a software update is released.

[JimTBob1976]

Having same issue, raised a complaint, but still no option available!?!

[BLUEOCEAN]

I have the same issue and I have the Sony XZ1 which I've had for 18 months.  WIFI calling used to work OK but recentyl the settigns have disappeared!!  Is this an issue on O2's part?

[PhoneChanger]

Hi @BLUEOCEAN do you have an unlocked version of one with O2 branded firmware?

There is an on/off issue with it on the new X1 however its new if its effecting older handsets

[BLUEOCEAN]

@PhoneChanger The phone was supplied by O2 in 2017 and is on an O2 pay monthly contract.  It is running O2 firmware.  I spent over a hour the other day on the O2 chat going through troubleshooting which included checking that it is O2 firmware - which it is.  Didn't get  close to solving the problem.  I was told I was getting transferred to a higher tier and got cut off!! It used to have all the settings for WIFI calling (in settings in the phone app) but they have completely disappeared.  I can't find any settings for WIFI calling anywhere on the phone!!

[PhoneChanger]

@BLUEOCEANthat sounds like the exact same issue that the X1 has, when it launched 4G Calling & WiFi Calling were all in the settings, a few days later they disappeared, then returned and have done this a few times since.

@Chris_K  can you shed any light on this?

[BLUEOCEAN]

I ran *#*#4636#*#* on the and you can see the greyed out options which I assume means they are not working!! (I'm not super techie in this area)

phone and 

[viridis]

The options for volte and WiFi calling appeared on my X1 today.

[BLUEOCEAN]

I seem to have inadvertantly fixed this issue on my Sony XZ1

Within the phone app, I went to 'Settings' | Calls | 'Accessibility'

I noticed TTY mode was set to 'off'. I set it to 'TTY full' and rebooted the phone.

Within the phone app, I can now see 'Wifi Calling' as an option within 'Settings' | Calls |

I'd be interested to know if this works for anyone else?