I updated to 20200703, and no problem with torch nor Camera, works perfectly so far.
Mobile data issue was fixed by the update for me.
I can confirm the screen lock time issue, but I had it even before, noticed it when I installed Lineage.
Can confirm:
Can’t confirm:
How can I figure out, whether my torch/camera problem is software or hardware conditioned?
I’m not sure if the problem maybe did occur before 20200703, but I only recognized it after.
@chrmhoffmann First of all: Great work, pal, thx a lot for this cool stuff! 
LineageOS running very fluently, I am really satisfied!
Just wanted to let you know that the information about the battery model installed is missing in “About the phone”.
Not sure if you’ll find any useful informations with it, but the Fairphone Checkup app on fdroid may help you to know (never used it myself though).
Installed 17.1 on my Fairphone 2. Did not install Gapps as I never use them. Everything worked correctly but the phone overheated. Once too hot, erratic behaviours and systemwide crash. I saw this before with Fairphone 2 running Fairphone Open. I solved it then by installing an app to turn off unnecessary background processes and keep CPU cool. This time, could not find an app able to identify and stop unnecessary CPU activities in Lineage 17.1. Now awaiting new build of Lineage for Fairphone 2 without the CPU abuse.
Also installed Lineage 17.1 on Moto G Titan and there it is totally stable, and runs cool. Not sure if this helps i.d. the actual glitch(es) on Fairphone 2 / Lineage 17.1.
If there are details you need to know, ask me. I will try to help.
Despite such glitches, nice work. Much appreciated.
Will keep using Lineage on my various devices as it helps keep devices useful years after manufacturers stop supporting them. Android 10 on my Moto G which was running Android 4 is quite a refurbishment - keeps a good phone in use not in recycling, has to be better for our planet. Well worth a monthly donation to help the developers!
Thanks for your advice. But per description Fairphone Checkup unfortunately can not check the camera, but only some other hardware.
Since version 20200703 no more problems so far. Seems to have been solved.
Thank you. 
Mobile data works for me. The only issues I have are:
With the stock app or with every app? Is there a difference if you use another app?
With the stock app. I didn’t try another app but will do.
I had the same problem with early versions of Lineage 16 and it disappeared after a few updates…
Now I’m on 20200710, but the issue, that the main camera and torch seem not to exist and they are not missing by the software, still remains.
@CarinaS Can you say since which update this issue occurs to you? I am thinking about a downgrade to try to fix it.
If you use Signal, you can also use this app for sms.
Maybe this helps you further?
Steven
It seems that some have the “No Mobile Data after flight mode on/off” problem. At least more than those of you who don’t have that problem.
I also have it with 17.1-20200710-NIGHTLY-FP2.
Because I use flightmode often (several times a day), I tend to go back to 16.1.
Unfortunately it looks like I have to install everything completely new. A first attempt to install the 16.1 image tells me LineageOS that my encryption password is correct, but it cannot boot any further. LineageOS offers me the factory reset at this point.
Back to 17.1 the Fairphone will boot again with encryption.
Yeah, that’s pretty annoying. At the moment it’s not too bad because I just reboot it maybe once a day, but when I’ll get back to working regularly in autumn it will soon be getting on my nerves. For me downgrading is not an option though.
I mentioned that earlier: For me least the mobile data on/off/on works repeatedly after shutting down the phone completely and then booting it up again. A reboot didn’t always help.
For the SMS issue to me it looks like this only happens when the phone is in energy saving mode.
That’s true for any downgrade.
What can help is to make a backup of App+ their Settings with e.g. Titanium Backup, so you don’t have to reconfigure everything
I did downgrades to figure out whether my problem, that the main camera and the torch are not working since one of the last updates, is software or hardware conditioned.
The oldest version I downgraded to was 20200529. Lineage wasn’t working smooth (I could not leave the lock screen), but I had access to Open Camera: there was no ability to switch to the main camera, although it definitely still worked in June.
Now I am back on 20200710 and LOS works fine again, except torch and main camera.
So it seems I have to buy a new camera module. But I still wonder that there is not any error message and it seems the software is not missing main camera and torch.
Even a barcode scanner now uses the selfie camera instead of the main camera, although it always used the main camera before and there is no error message telling me that it can’t find it anymore.
So to me it also could be a software fault. But why I am the only one with this issue? I did not install any special additional software, no gapps, no modem files, but only Magisk.
I also have magisk and don’t have any of the issues mentioned recently.
If you take the top module away and start the camera, what happens?
Is it save to run the phone without the top module? I’m afraid to damage it or at least the software.