[][][Xperia 10II] losing cellular network after call

Unfortunately the bug still exists in EA on my Xperia 10 II.

Indeed, it takes almost exactly 150 seconds (2,5 minutes) to reconnect (SFOS, Xperia 10 ii, Telekom Germany). That is way too long.

Incoming call causes switching from 4G to 2G and thus cuts mobile internet. Once the call is finished, reestablishing a data connection with 2G takes more than a minute. However, the 2G data connection is automatically cut after a few seconds and for little less than 1,5 minutes no network access at all exists. Only thereafter 4G is back.

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I’ve been able to send some Video and Logs of that to Jolla. Also I detected, that this only happens to me if WiFi is off. Reproducible. What i didn’t test, is the condition that WiFi is on but no network available. Perhaps someone can confirm that as well.
By the way, i think mine connects back in like in 36 sec or so.

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Indeed, in my test I switched Wifi off. Reconnection depends on the quality of the mobile network. In our office the network is weak. This could be the reason why restoring mobile data connection took so long.

However, the steps are always the same: falling back to 2G for a voice call, after the call reestablishing a first data connection with 2G, then killing all mobile network access completly and eventually establishing a new 4G connection.


Unfortunately, this bug is still present in SFOS
The problem still occurs when mobile data is on and no WIFI is available.

Because of the last posts in this tread and the 3rd software version of SFOS 4 for Xperia 10II, I tested my t-mobile Germany SIM card again in the XperiaX.
The result:
In SFOS, and the SIM card works perfectly in the XperiaX. When a call is made, the network switches from 4G to 2G and after the call back to 4G without delay and without interrupting the mobile network.
The same SIM card shows the bug described above in the Xperia 10 II (aarch64) in all three SFOS versions.

Note: The 3G network of t-mobile Germany has been switched off since 1 July 2021.


Add it to the list of bugs for me which is just making be super frustrated at my phone.
X10i, latest update.


Glad you made this observation because it could help finding the true reason for the annoyingly long network pause after each call.

It is about the same time when I got my Xperia 10ii and t-mobile canceled 3G. Therefore I might have wrongly assigned the long network loss after every call to the switching-off of 3G - and not to SFOS/aarch64. I will check with my older back-up XA2 in order to confirm your observation

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This annoying bug still exists in SFOS EA. It is exasperating…


Yes, it is annoying. On my XA2 Plus I have also no Internet/Data Connection during the calls.

Five days ago I tried to fix this bug by flashing the phone with Android 11. I used it for a day, making and receiving calls. Both to different mobile providers and to landlines.
I sent and received text messages and surfed the internet.
Then I flashed SFOS Unfortunately without result, the bug is still present.

@flypig Why have you tagged this bug report as fixed?
Have you fixed this internally and will we get it with the next OS update?
The bug is still present in SFOS

Hi @silta, Thanks for pinging me about this: I’m glad you’re on the ball keeping track of things.

The community bug coordination team is cleaning up the bugs in the forum, and one of the steps has involved tagging all bugs that are noted in the release notes as having been fixed. There are over a hundred bugs like this, so there’s always a risk we make a mistake in the process.

In this case, this bug was reported as fixed in the release notes for Sailfish OS 4.2.0 Verla (it’s the very last bug in the list there).

Looking through our internal database, a number of changes were made to fix this issue, the decisive one being this change.

However, clearly you’re still experiencing problems.

It’d be really helpful to know whether the problems you’re experiencing now are identical to the ones you describe in your original bug report, or whether there have been any changes resulting from the fixes that have gone in?

Hi @flypig. The fixed bug in the relaese notes 4.2. does not refer to my bugreport. It refers to post #19 by @KuroNeko in my bugreport.
Unfortunately, he “hijacked” my thread.

Here again in brief:

german t-mobile simcard in X 10 II.
mobile data active.
After a phone call, the entire connection to the mobile network breaks down after the symbol for 2G appears very briefly in the upper right corner.

Even after deactivating flight mode or switching on the phone, it takes a very long time until a connection to the mobile network is established.

The loss of connection to the mobile network after call does not occur if there is a connection to a Wi-Fi network at the same time.

It should be noted that T-mobile Germany has already switched off 3G.

Interestingly, the exact same SIM card works in an Xperia X under the same conditions without any problems.

I recently tested all this with a Vodafone SIM card to rule out the possibility that it was due to the German t-mobile network.
Unfortunately, the result was the same.

That’s why I think it’s because of the 64bit version of SFOS.


I may add that I have exactly the same behavior @silta is experiencing with X10 and Vodafone Germany. With my XA2 and Vodafone the bug is not present. VF also shut down 3G a while ago.


I also tested it several days ago with a Vodafone card. The same behaviour. I made an edit in my post before. Thanks for your confirmation.

Thanks for clarifying @silta, and for the confirmation @spark. That all makes sense now.

Concerning the original bug then, I can make a fresh internal bug report to cover it. However, one thing I want to be clear on is that this isn’t just the consequence of lack of VoLTE support on your phone.

I appreciate what you say about the fact your Xperia X doesn’t suffer from the same issue, but I just need to clarify.

Currently, without VoLTE support, and without a 3G network to fall back on, your phone will drop back to 2G during a call, meaning there’s no data connection. This is all correct behaviour. After the call it should then return to 4G with a data connection.

Is the Xperia X nevertheless dropping to 2G and then returning back to 4G quickly? In the case of your Xperia 10 II, if I understand correctly you see the same behaviour except that it takes considerably longer to return to 4G (could you clarify how long in both cases please?).

I’m sure I’m repeating things that you’re well aware of, or have already covered above, but it’s just helpful for me to be certain about these points.

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yes, understood and correct. The issue (for me) with the Xperia 10 lies in the long period to get back to 4G with no network at all meanwhile. As stated, after the call (which took place in 2G) the phone is without network, supposingly while trying to re-establish the 4G connection. This usually takes 20-30 seconds, even while being in a city center with perfect coverage.

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I’m aware of that.

Yes, the Xperia X turns back to 4G immediately.
The X 10 II needs mostly 20 - 60 seconds. During this time there is no cellular network available.

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On O2-Germany it also takes about 10-20 seconds (but not 60) to reestablish 4G connection after a cellular (2G) call (or call attempt). Don’t know if 3G is still in use at all.
I understand this behavior might be annoying for some users (while it doesn’t really bother me) and I expect this issue to be fixed (or vanish automatically) once VoLTE functionality is available eventually.

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