FP4 with dualSIM loses network connection on a regular basis

I have been using dualsim on my fp4 (with latest Android13 update) for two months now, and I am really underwhelmed by the performance/useability.
Both sims, esim and physical, are from the same carrier, congstar, with is a telekom reseller in Germany.
I have set the esim to phone calls and the physical to data.

The problem is - several times a day, one or both sims will lose network connection completely and fail to reconnect for a LONG time. Even if there is visible connection, the exclamation mark stays. It looks like that:

Enabling flight mode for a few seconds doesn´t fix it.
Disabling one of the two sims for a while fixes it for some time.
Most of the time, it “fixes” itself after 20 minutes or so. Which is, imho, not really satisfying to go that long without data connection.

This has been happening since I use dualsim.
Can anyone tell me what the cause of this is?


Is there any correlation between your location and the loss of connectivity (e.g. on your way to work or something)? I’ve been using my FP4 with dual SIM functionality for a long time now (with SIMs from different providers) and never experienced serious issues that weren’t coverage related. I mostly use connection when I’m in the train on my way from Germany to Austria, although it doesn’t necessarily happen synchronously, as the two SIMs use different networks. The fact that both of your SIMs fail at the same time may simply be due to them connecting to the same network.
The Phenomenon of the exclamation mark staying there for a little bit although the triangular reception indicator is ‘filling up’ again already is usual behaviour when re-entering a region with better coverage. So I wouldn’t put to much weight on that.

Thanks for the reply.
Sadly, there is no real correlation there. while it does happen more often while I travel (thanks to the notoriously bad german cellular network), it also happens while at home.
The problem with the exclamation mark staying there is simply that it´s often there for several minutes, meaning several minutes of no data connection, which didn´t happen with only one sim in the past.


On my side I have twice the same operator and sometimes my e-sim (the one I use most of the time) disconnects. I disable reenable the profile and it fixes the issue for a while.

Hope that can help.



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I have the same/similar problem. In my case I have SIMs from 2 different (eurropean) countries as I daily cross the border for work, meaning that the SIMs are often switching provider (home to roaming and vice versa). For me the exclamation mark is present even if the triangle states the signal strength is not bad.

I used to be bugged by spontaneous reboots, but now I cannot use the phone unless I switch off one of the SIMs, which is very unpractical.

If there’s anything I can do to help debugging the problem, please, let me know.


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There’s already a thread about that issue

Workaround is simply to very briefly turn off and on the data connection again from the pull down menu in the status bar.

Hope contactsupport working on that already.

Just wanted to chime in after a while with a update…
I was very fed up with that issue, because in addition to not be able to call / use data during the disconnection times, it also drained the battery in no time.
So I opened a support ticket; the phone went to the FP repair center in France and they sent it back after a week, stating they fixed the software issue.
I didn´t try again because I already bought the fp5, which didn´t have that issue, because I needed a working dualsim phone for work all the time and couldn´t wait a week or two, and who knows if it works then…

I sold the repaired (?) phone, and the issue is solved to me.
A bit sad, because I liked the fp4 round body more than the not as round one of the fp5… at least, it has a new owner now who might be happy with the fp4. I would be, too, if I´d only used one sim card.

Hi all,
I have same problem, a (private) physical Dutch SIM and a (business) German eSIM, crossing border on a daily basis. Only the physical SIM randomly looses connection, sometimes several times a day, some days not at all.
Regards, Jaap.

There’s a whole thread here

So far no workaround or fix found.
Please make sure to report it officially too since they’re investigating already and perhaps some of your details help as well.

@bm90001 I sill dont think the topic you link is initially about the same issue, because loosing network connection is not the same as the device not recognising the SIM. Overall we have now 3 topics about network issues when using dual SIM partially mixed with different problems. As the OP here has marked their issue as solved I will close here and move some posts to one of the other topics probably.

Everyone having problems with mobile data connection when using dual SIM please head over to this topic

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