Wifi calling not working for T-mobile USA

[bcdixit]

Please answer the following questions for yourself before submitting an issue

• [x] Filters were updated before reproducing an issue
• [x] I checked the knowledge base and found no answer
• [x] I checked to make sure that this issue has not already been filed

AdGuard version

4.9

Environment

• OS version: HyperOS 2.0 ,Android 15
• Device: Xiaomi 15 ultra

HTTPS filtering

• [ ] yes, I do

Root access

• [ ] yes, I have it

Integration with AdGuard VPN

• [ ] yes, I do

Routing mode

Local VPN

Ad Blocking

EasyList

Privacy

AdGuard URL Tracking filter, AdGuard Tracking Protection filter, EasyPrivacy, Legitimate URL Shortener, Peter Lowe's Blocklist, Fanboy's Anti-Facebook List

Social

AdGuard Social Media filter, Fanboy's Social Blocking List

Annoyances

AdGuard Cookie Notices filter, AdGuard Popups filter, AdGuard Mobile App Banners filter, AdGuard Widgets filter, AdGuard Other Annoyances filter

Security

Online Malicious URL Blocklist

Language-specific

No response

Other

No response

Which DNS server do you use?

DNS protection disabled

DNS protocol

Regular

Custom DNS

No response

What Stealth Mode options do you have enabled?

No response

Issue Details

Steps to reproduce: Ensured "make calls using WiFi" switch is ON in Settings →Mobile network

1. Adgaurd App running with toggle ON
2. Wifi conncted
3. Enabled airplane mode with Wifi ON and mobile data off
4. Expected VoWifi symbol with Tmobile Wifi calling.
5. Disabled airplane mode to restablish cellular connection and wifi ON
6. Turned off ADguard in app by flipping toggle switch
7. Turned ON airplane mode.
8. Phone VoWifi symbol appeared on top right corner.
9. Made and received test call calling works
10. Turned ON Adgaurd protection by flipping switch in App .VoWifi persisted and calls were successful.

Expected Behavior

VoWifi / wifi calling should be activated irrespective of Adgaurd app on Android is active or not

Actual Behavior

VoWifi / wifi calling only works when Adgaurd is turned off in Adgaurd app.

Screenshots

Screenshot 1

Additional Information

In Advanced → low level settings → IPv4 ranges excluded from filtering, i already see 208.54.0.0/19 in there . Added 66.94.0.0/19 as per article below https://www.t-mobile.com/support/coverage/wi-fi-calling-on-a-corporate-network.

Made no difference to behaviour.

[zamanmh1]

Very similar to my issue #5660 also have Xiaomi 15 and have added IPs for my network. Also added a screen recording of the issue.

[bjorktribe]

Same issue on OnePlus 13 | OxygenOS 15 | Android 15. Additiionally, calls go straight to VM within perhaps 10 - 15 minutes of adguard being enabled. SMS stop being received as well (RCS works fine). Happy to provide additional details as needed.

[ESurina]

Please try adding these same IP addresses to IPv6 ranges excluded from filtering and enable IPv6 filtering. Let me know if this helped solve the problem.

[bjorktribe]

@ESurina there are no ipv6 ranges mentioned in this thread. If you mean for us to add the ipv4 address to the ipv6 allowlist, adguard does not allow that format. I do have ipv6 filtering enabled.

[ESurina]

In order to troubleshoot this issue, we need to get your system logs.

Here's what we need you to do:

1. Get to a state where VoWiFi is active.
2. Collect logs: -use this manual
3. Send this file to [email protected]:
   • include [android] keyword and 5735 in the subject of your email
   • specify the exact time when the issue occurred

[bjorktribe]

Report sent @ESurina, thank you.

[bjorktribe]

@ESurina can you please follow up here? Much thanks

[zamanmh1]

Looking for a follow up too please.

[bakoscsaba]

I have the same issue using OnePlus 13 | OxygenOS 15 | Android 15 on Magyar Telekom (Hungary). After boot voWIFI connects but after some time (10-50 mins) the voWiFi status bar icon disappears and wifi calls are not working anymore. Turning WiFi or airplane mode on and off does not help. I have tried custom DNS providers but there is no difference. If I add the DNC provider in the phone's private DNS setting, voWIFI works as expected. Also tried using Proton VPN to see if the conflict is with the VPN connection but voWIFI stayed connected so the issue is clearly with AdGuard. By the way https filtering is turned off.

Strange thing is that my other phone which is a Nokia X30, using the same operator and AdGuard settings does not have this issue.

[bakoscsaba]

I did a bit further testing. The voWIFI icon sometimes disappear even when AdGuard is turned off, but after few seconds it always comes back. My guess is that when using AdGuard the re-registration is somehow blocked. Actually it can be reproduced when the voWIFI is still active and I turn off WiFi then back on, the voWiFi never activates again.

@ESurina Is there any setting that could help in this regard? Is it possible for you to verify this? If logs are needed please let me know.