[][Xperia 10II] No Internet connection on Mobile Data when leaving WiFi if `Data acces point`: `Protocol` is set to `Dual` (default)

REPRODUCIBILITY (% or how often): Not sure yet. Experienced multiple times.
BUILD ID = OS VERSION (Settings > About product):
HARDWARE (XA2, Xperia 10…): 10II
REGRESSION: (compared to previous public release: Yes, No, ?): ?


Some websites and apps suddenly have no access anymore to most of the websites while recently visited websites (like the default search engine) seems to work fine in some cases. Most of the time e.g. the default search engine in the native browser still works, but not the others. Or Fernschreiber (telegram client with tdlib) can access the network, but other apps like Piepmatz can not connect to twitter.
A reboot does help. Restarting networks from “Hilfsprogramme” does not.


After changing from WiFi to mobile date.
Telekom.de SIM
EDIT: Settings -> Mobile Network -> Data acces point: Protocol is set to Dual


  1. Change from WiFi to Mobile Network
  2. Go to Browser and start to open websites


All websites work fine


Most internet applications does not work. Android and native apps are affected. Internet Sharing is also affected.


1 Like

Seems like you only have an IPv6 connection, without IPv4 support.
Go to Settings -> Mobile Network -> Data acces point and check that Protocol is set to either Dual or IP.

Thanks for the Idea. It is set to Dual, not IPv6. But next time I see the Error I’ll try to change it to IP and see if it changes something.

Ok, I tested it. After leaving the WiFi again I had the same Issue. I changed from “dual” to “IP” and restarted the network. Then it worked. Then I switched back to Dual. It still worked. Then I went back to the WiFi. Then again WiFi of → same Issue.

So: “Dual” to “IP” seems to be a workaround. But Seriously: I want IPv6. So I assume there is a Bug somewhere.


I’ve seen this, but pretty infrequently. So infrequently I wondered if I was imagining it, but still . . . I’ll mess around with the v4 vs v6 a bit and see if I notice any pattern.

1 Like

Update: With staying at the ip selection for the protocol i never had that Issue again yet. So the workaround seems to be somehow ok for the moment.
I’m willing to provide more logs or data that help to iron that out if someone tells me what they need!