Please can you try to give me exact APN settings which actually work for you … then we could try to match them against apns.config.xml … later see what changes after an update … and again after your carrier APN reset … to see in what way an update changes your APN setting adversely.
Or step one show me the published APN settings for your carrier and plan.
Offer open to @BST if you like !
Thank you for trying to help. Currently, I have no APN settings that keep working. If I reset APN settings to default the phone reconnects in the same manner as a restart would do, but then it has the same behaviour as decribed above. If mobile internet has been turned off and then on, or if wifi is turned on and then off, the connection will be unstable with every APN setting I have found for KPN as a provider.
I am really not sure @BST but the report in Post #14 looks to me similar to a “lazy connection” from your carrier.
Conversations with a carrier can become infuriating, I know, but maybe there are “local issues” ?
I do not mean to just deflect responsibility from /e/OS … is just a thought.
In Settings > Network and internet > Mobile network > Preferred network type > I have always been able to use “(recommended)” (locally it is LTE). Does 4G show recommended for you ?
To check the signal strength on the phone, Settings > About phone > SIM status > Signal strength.
Checkout Ideal Cell Phone Signal Strength https://novotech.com/learn/m2m-blog/blog/2022/12/20/the-ultimate-guide-3-ways-to-check-lte-4g-or-cell-signal-strength/.
Thanks again for trying to help, really appreciate it. I understand why you would say that, but if I put my SIM into a Xperia XA2 with e/OS/ on it, there is no problem so I don’t think the carrier is the issue here.
I even bought a Samsung of the same type that is sold in the shop with e/OS/ to test this, and also in an S9+ there is no issue, so it seems specific for the Fairphone3 (for me at least). I’ve used the FP3 for 6 months with previous versions of e/OS/, and then the issue did not exist. I turned 4G on several times a day after leaving the office or home, and it always worked. I updated it to 1.15 and then the problems started.
And to awnser your question about 4g: yes, this is indeed shown as recommended.
The mobile network in Signal strength says connected, in service, Signal Strength -102dBm 37 asu. For the other KPN sim it shows -100dBm 40 asu. That seems bad according to the site link. Perhaps the FP3 is not very good combined with this provider.
I’ve also tried this with a Pixel4a with e/OS/ (as you can see I am really motivated to find out what is going on) and it works fine with -101dBm 37 asu. I’ve turned wifi on and off multiple times, and 4g connection is restored and works without trouble. I have the impression that it is specific for the FP3.
What I have noticed here, is that if I activate the network traffic monitor, that always shows on the P4a and on the FP3+ it turns off. Is that perhaps an indication that the connection is lost?
That seems different to my phone. If I turn on network traffic monitor and place the phone in a powered down microwave oven the monitor stays open and registers zero traffic.
I’ve also noticed something interesting. If I take out one of the SIMs and put it in the Pixel (which only has one sim slot), both seem to be stable with one sim in them. If I put both sims in the FP3+, they both become unstable… so maybe it had something to do with how the software handles 2 sims?
Okay, that is different behaviour. Perhaps it is also related to the provider in some way. I think the way the sims behave in separate phones and together in one also may have something to do with the original problem. Perhaps it is a combination of both, provider and the fact that both sims are in the same phone.
I suggest it would be worth looking through the Gitlab issues fp3 is selected in this Gitlab – Issues link; if you find nothing similar you might consider to Report an issue I think there are unusual features in what you are seeing.
Just to give an update, I’ve percieved the following: after I switched the data connection from one sim to the other in SIM settings, the connections appeared to be stable for at least a day. Once I rebooted the Fairphone, the connection became unstable again.
Just to try it out, I got a e-SIM for the Pixel4a to see if the problem persists with the use of 2 sims with this carrier. I’ve used it for 3 days now, and the connection stays stable if I turn 4g on and off. The behaviour of an instable connection therefore seems specific to the Fairphone, since both the Samsung and the Pixel I have tried with e/OS do not have the same behaviour. I will report an issue in gitlab.
I am also still having the same problem as you have. Did you find out anything new? After the last update the whole circus of the bad 4G connection has returned. I am not using wifi so I depend o 4G. I also use dual sim like you do.
Unfortunately for FP3 users, I’ve noticed that the problem does not happen on both the Pixel4a and Samsung I have tried. I’ve used the Pixel for more than 2 weeks now, and can confidently say that the problem does not exist on that device. Since I had the same problem over and over again on the FP3+, I am now sure the problem is device specific. Since I do need a stable connection and 2 sims for my work, I have decided to discontinue using the FP3 because the 2 sim feature does not work well enough to use.
Thank you very much for letting me know. That saves me a lot of time and frustration. Do you still like E/OS? What about LibreOS? Do you have any suggestion what phone to switch to. I tried installing E/OS on a ONEPLUS 5 but that did not work. Thinking about buying a samsung galaxy 7.
Do you think this problem would also be there using just one sim? I read you tested that out.
I love E/OS and will keep using it. I’ve made donations to the E.foundation every december since I started using it and will keep doing so to keep the project alive. I also encourage others to use it, so you can consider me a big fan. I’m also a big fan of Fairphone, but there must be something with the hardware that does not make the 2 work together and then I love E/OS more than the Fairphone.
I used a Galaxy S9+ to install E/OS on and that worked flawlessly. Use was very good and speedy enough for daily use. I use a Pixel4a with E/OS as daily driver now since I like the size (don’t like mega big phones in my pocket) and works perfectly with 2 sims (one e-sim since it has only one physical slot).
The problem with the FP3+ did not happen when I used just one sim. It must be something in the dual sim configuration which makes the glitches. Hope these awnsers are helpful.
Yes these answer are very helpful. Thank you very much. I already thought about the S9 and good to hear it works fine. Installed e/os on S7 for my girlfriend and seems to work flawless too. But yes must be something to do with the dual sim. Have a good day an thanx for helping to bring this quest to an end 
Decided to sell my Fairphone and bought a Galaxy S9. Does dual sim work on that one as far as you know? Have a goof weekend!
Galaxy S9+ worked flawlessly with dual sim, so I expect the S9 to work fine as well.
Yes I am very happy with my new secondhand S9.Works like a charm. No problem with dual sim whatsoever. Thanx for your help and have a good weekend!