Android subsystem loses connectivity when switching networks

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 4.3.0.n
HARDWARE (XA2, X10, X10 II, …): XA2 Plus
UI LANGUAGE: English
REGRESSION: (compared to previous public release: Yes, No, ?): New in 4.3.0

DESCRIPTION:

After changing the data source (between wifi, mobile or none), all the Android apps I use lose data connectivity, and do not regain it after returning to the original data source. It’s necessary to restart the Android subsystem each time the data source changes.

PRECONDITIONS:

  1. Xperia XA2 Plus with wifi and/or mobile data plan.

STEPS TO REPRODUCE:

  1. Open Android apps (I only use APKPure, Slack, DSNote and the NZ Covid Tracer app).
  2. Verify that they are connected to the internet.
  3. Change the data source by moving out of wifi range or turning wifi off or, if on mobile data at home, by turning wifi on.
  4. Reverse the change in data source (return home or turn wifi on or off).

EXPECTED RESULTS:

A) The Android apps retain data connectivity after step [3] above if the phone still has an internet connection.
B) The Android apps resume data connectivity after step [4] above.

ACTUAL RESULT:

None of the apps is able to connect to the internet after steps [3] or [4]. For Android app internet connectivity to resume, the Android subsystem must be stopped and restarted.

ADDITIONAL INFORMATION:

This is particularly frustrating with DSNote, as forcibly stopping and restarting the Android subsystem loses local changes made in the interim. However, this is at root a Synology dev issue and not directly caused by the connectivity issue described above.

2 Likes

IMO this flaw is many years old, has been reported multiple times at TJC and TMO and affects at least all officially supported devices by Sony.
I have been observing it only on certain network transitions, e.g. Mobile → WLAN results in no connection, while WLAN → Mobile works fine.

You may research older posts reporting this at TJC and TMO.

Thanks - that’s useful to know. But I’ve never experienced it at all until I installed the first 4.3 release. Since then it’s been constant. My use patterns haven’t changed, either. Perhaps I should do a clean install.

It happens to me too on my XA2 Plus with 4.3 but turning flight mode on and off re-enables WLAN for android subsystem.

For me this started with the update to 4.2, but indeed significant numbers of people have had it longer.
As a workaround i set my APN setting for Internet to IPv4 only, and have barely seen it since.

Since the original issue(s) are still vague (no public analysis) i agree this could be viewed as a duplicate even though it is a different version of the issue.

2 Likes

Upgrading to 4.3 on the XA2 mobile data connectivity disappeared for everything (i.e. Both native and Android) until I set it to IPv4 only whereupon it returned reliably for native, but was still ultra flakey for Android and disappearing regularly. I’d really love to know why some people suffer from these problems and others don’t - on the same phone model and the same SFOS release. And its not just Android mobile data connection reluability either - there seems to be loads of issues that fall into this some-do, some-don’t category.

The first thing that comes to mind is how IP addresses are assigned to the phone. The mobile network can give you IPv4, IPv6 or both/dual. And sometimes not exactly what you asked for. I could easily see some things getting confused if the mobile network is IPv6 only for example, and WiFi is IPv4 or dual. Then there is a whole host of combinations with mapped addresses, dns-based online detection and whatnot. The Android App Support runs its own detection AFAIK, so different results are understandable.

This is the latest fix i have seen coming in, and should probably make it to 4.4:

I have never really seen any reports on native apps having switchover issues, but i’ll take your word for it.

[quote=“attah, post:7, topic:9833”]

It wasn’t that native apps had switchover issues, it was that I got no mobile data whatsoever after upgrade to 4.3 when the data access point was set to ‘Dual’ (on EE in the UK), the same as it had been on 4.2 and worked before the upgrade. The phone just got stuck in a ‘connecting’ loop where it constantly seemed to connect, then after a few seconds disconnected, then connected again and so on. Aftet setting it to ‘IP’ then it connected successfully and stayed that way for SFOS apps, but still had the switchover issue for Android. Jolla must have done something between 4.2 and 4.3 to make ‘Dual’ no longer work for EE in the UK therefore.

You should probably look at the post formatting a bit; your reply got mixed in with the quote.
Well, in that case, the fix i linked is definitely for you as the commit message sounds exactly like what you describe.

Hmm, yes I now see that my post was mixed in with yours. I used the ‘reply’ function on @szopin 's Forum viewer on my Sailfish phone rather than than the web site and think it may be a bug when replying to long posts such as yours using this app. I’ve also noticed that when you use the ‘reply’ functionality in this app it initially quotes the post being replied to, but then if you later look at your own replied post again the quoted text is missing and the forum indicated that the post has been later edited (which it hasn’t), so definitely something strange going on here.

I’ll edit my previous post on the website to tidy it up.

Yep, that was my problem exactly. I assume what connection types are offered must therefore vary by mobile operator and perhaps country.

Thank you; that’s a timesaver, and I’ll try it today.

I’ll give the APN settings change a go.

Same issue here on Sony XA2 with a singe sim card.

I use the ‘Restart network subsystem’ option about 6 - 7 times per day in order to recover the connection and then receive the missed instant messages. I even have a shortcut for it on the main menu to do so.

I was also thinking to do a cron job to simply restart the network subsystem automatically each 5 minutes to avoid any issues. Would this be easy to do?