non-lockdown VPN (IPv6 carrier)

Three1989

device: 6a
build: TP1A.221005.003.2022101800
carrier: TMobile, tmobile_us-40000000018.7 (unable to select APN

I am experiencing inability to have mobile data, using these settings:

Always-on VPN = (off)
"Block connections without VPN" = (off / greyed out)

From another thread (pertaining to P7 experimental build), the lockdown mode issue with VPN on IPv6 carriers is acknowledged in this way:

strcat There's a known compatibility issue on Android 13 between the improved VPN lockdown mode and mobile data with certain IPv6-only carrier configurations. Try changing your APN configuration from IPv6 to IPv4/IPv6.

My VPN works on wifi, but not over mobile data, with no "lockdown mode" configured.

Is this the same known, upstream issue? Or do I have a separate/different issue?

Thank you.

unwat

Three1989
Sounds like the same issue.

You can try this workaround:

Turn off block connections without VPN.
Toggle airplane mode.
Connect to VPN
Go back to settings and turn "block connection's without VPN" back on

There's another fix others have been sharing on here:
https://discuss.grapheneos.org/d/1426-vpn-issue-experimental-build-on-pixel-7-pro/2

I personally haven't experienced this issue, so I haven't changed my APN settings. I don't know if it's easy or not... However, if you can change to IPv4 there, this problem will go away, so I've heard.

MetropleX

Three1989 (unable to select APN)

I note you mentioned you cannot select APN, what you have to do is create a new VPN with the same values but changing the IPV6 to IPV4 and use the newly created one.

This has been known to work by another user: https://discuss.grapheneos.org/d/1025-t-mobile-always-on-vpn-fix/4

Three1989

unwat

This VPN issue is presenting itself with "VPN Lockdown" disabled:

Always-on VPN = (off)
"Block connections without VPN" = (off / greyed out)

... so will the workaround you describe apply?

Turn off block connections without VPN. <-----
Toggle airplane mode.
Connect to VPN
Go back to settings and turn "block connection's without VPN" back on <-----

VPN

MetropleX

Three1989 please try the latest build (select Alpha/Beta Channel if required):

backport many upstream fixes for clat including a more complete set of fixes for the compatibility issue impacting all Android 13 operating systems between VPN lockdown and certain IPv6-only mobile data configurations along with fixing other issues with these setups

Test and report any issues to our Alpha/Beta Room on Matrix: https://matrix.to/#/#testing:grapheneos.org

Three1989

MetropleX

If someone has followed this suggestion (changing Access Point Names settings manually, to "change, APN protocol to IPv4/IPv6 instead of set to just IPv6") ... then is it best practice to revert these changes, now that the upstream Android code issue is apparently fixed?

Sorry to reply in 2 places, with the same concern -- trying to be visible for the others who were attempting workarounds over last couple months.

I appreciate the heads-up.