New Prefer vowifi not working

[eng333]

Using 14 Ultra with 1.0.15 rom.
I tried *#*#869434#*#* and enabled the "Make calls using Wi-Fi" option. it says it will do it "whenever possible"
I find that it never uses voWIFI. I have to enable airplane mode and connect to WIFI, in order to use WIFI for a call.

Note, I do have "Use voLTE" checked as well, but the entire setting is greyed out. Not sure if that affects anything.

 

[gogocar62]

In addition to activation, do you also have "prefer VoWIFI" set?

 

[eng333]

In addition to activation, do you also have "prefer VoWIFI" set?

I don't have that option on my screen. I dont have "Use voNR" either.

 

[arosado]

In addition to activation, do you also have "prefer VoWIFI" set?

Can we get more assistance on this? My wifi calling sometimes turns on and off randomly.

 

[Birraque]

I don't have that option on my screen. I dont have "Use voNR" either.

If you're missing some network features these dial commands can help:

*#*#726633#*#*
- Enable 5G SA Network option

*#*#34834#*#*
- Enable Prefer 5G option in the Preferred Network Type if supported by your SIM Card (Carrier)

*#*#8667#*#*
- Enable VoNR (Voice Over New Radio) option when 5G NSA/SA network

*#*#86583#*#*
- Enable VoLTE (Voice Over LTE) option when 4G/LTE and 5G NSA/SA network

*#*#869434#*#*
- Enable VoWiFi (Voice Over WiFi) option when 4G/LTE and 5G NSA/SA network

NOTE: Check if your line has the VoWiFi provisioned on your line in the Carrier side too... *#*#4636#*#*

 

[eng333]

I have all that enabled. VoWIFI works.
The issue is that it is not "preferred" because I lack the option "Network Preferences: prefer wifi" and thus vowifi only works when I turn on airplane mode (and wifi)

 

[arosado]

Found something that may be useful.

We have:
*#*#34834#*#*
- Enable Prefer 5G option in the Preferred Network Type if supported by your SIM Card (Carrier)

However, I've noticed that occasionally the phones preferred Network Type resets itself.
Type: *#*#4636#*#*

and inspect your phones preferred network type, select: NR/LTE or depending you can select a different one but make sure NR/LTE is selected. It triggered my (VOWIFI) to turn on.

Is there a possible way to force this to stick or stay on? Possible bug or is this a carrier thing?

 

[eng333]

I have "Prefer 5G" OR "Prefer LTE" but not NR/TE option.
VOWIFI turns on if I have airplane mode on.
My issue isnt with "preferred network type" (ie. "Prefer 5G"), it's with "Network preferences" missing so I can't select "Prefer vowifi"

 

[TheGunR]

I'm having exactly the same problem: I cannot see "prefer VoWifi" and therefor cannot turn it on.
I know that my carrier Deutsche Telekom want's to handel the decision on the network side while other carriers like O2, Vodafone and 1&1 let the device define the preference.
Is there a way to overrule this decision?

I need the "Network Preferences: prefer wifi"-option.

 

[gogocar62]

Enter the string * # * # 869434 # * # * in the field for dialing numbers, a message will appear after the last character, which must end with DISABLE. If ENABLE, we repeat the string again. This will allow VoWiFi because this menu is hidden by default.

But maybe I misunderstood your request.

 

[Scream4coffee]

Mine is not a bug, I am almost sure about it, but still;
Using Mi14, HyperOS2, latest stable.

VoWifi on SIM2 (KPN NL) works flawlessly, connects immediately, anywhere anytime, as usual.
But for SIM1 (VODAFONE TR) no way.
it was working last week, and this week I updated from HyperOS1 to 2

I am aware of the following, checked whatever I can read especially from @gogocar62 and all other helpful people, with much thanks. The last resort would be the MBN settings maybe, but I am afraid of wiggling those scary gray 3-letter buttons without some help.

*#*#726633#*#*
- Enabled 5G SA Network option

*#*#34834#*#*
- Enabled Prefer 5G option in the Preferred Network Type if supported by your SIM Card (Carrier)

*#*#86583#*#*
- Enabled VoLTE (Voice Over LTE) option when 4G/LTE and 5G NSA/SA network (last digid says disabled)

*#*#869434#*#*
- Enabled VoWiFi (Voice Over WiFi) option when 4G/LTE and 5G NSA/SA network (last digid says disabled)

- Can see VoWiFi provisioned on *#*#4636#*#*

Talked to the carrier, disabled/re-enabled VoWifi services (4.5G, 5G, HD Voice etc)
Did full reset to connection settings, lost many wifi/bluetooth profiles, but was no big deal only if it helped...
The iphone device using same sim provider, can connect fine, changed the sims, and it doesnt connect when on my SIM1 or SIM2, also if I switch my simcards between SIM1 / SIM2, then KPN connects and my sim cannot. But My sim can connect when in iphone.

So after all these trials, then I thought it is beyond my knowledge. and here I am.

Edit: AI says iphone has single:multiple connections, but Xiaomi HyperOS has ephemeral port changes during handshake and Vodafone doesn't like that. But KPN is fine with it. So I did NAT-T on pfsense and tried fixing static ports too....and another long story with fw rules and etc. Finally now I m back to square1.