In my experience sporadic problems like this are generally caused by contact problems and cleaning them (even if you’ve really cleaned all of them) may not be enough: often the problem is mechanical in the FP2, so make sure all contacts are not only clean but firm.
If you have a SD card make sure it’s configured as removable. If not, take steps to make it so. See also here. Once it is removable, try removing the SD card and see if this makes any difference to your experience.
As to Android versions I would recommend updating to the latest available (currently Android 9 but 10 will be coming soon). See links to other info and the bug tracker on that page too.
My FP2 is currently running a beta version of /e/ Android 11 with no significant problems.
Thank you OldRoutard. I had searched the forum, but not with the right keywords I guess… By the way, there is no SD in this phone.
You gave me ideas, and I did some tests, e.g. changing the screen (we happen to have 3 of those at home).
With all modules changed, and many OS tried (FP OpenOS, regular FP, LineageOS, all ranging from Android 7 to Android 11), I guess the only thing I did not try, is changing the motherboard, as suggested in the links you provided (apparently mainly because of the GPU).
More over, I strongly suspect, that there is a hardware issue, with all the strange and unrelated issues this phone has. Not only the battery indicator, and the display artefacts, and the phone freezing on receiving a call, but also:
recently, the phone freezing while the wake-up alarm rang, and only removing the battery could make the alarm stop;
the background resetting to the FP factory background (forgetting the custom one) once in a while;
and today, a very “interesting” report of the current hour:
I have similar problems, though not as bad (yet?): The same graphics errors (patterns), occasional freezes, app closings and reboots. Also here the freezing occurs with high probability when receiving or giving a call. Apps do close especially when being more compute or graphics intense.
So, should you get further with this, please report back here, as I’d be very interested to hear about causes (and cures).
Hello, this is probably my last post in this topic.
After all my latest experiments (see previous posts), I ended up having replaced all modules (except the core “motherboard” of course, else it just wouldn’t be the same phone ). And to my surprise, the phone worked really better!… for a while at least. Then problems began anew, more and more unpredictable.
So there is probably a combination of ageing hardware with electrical contact issues as well, with the whole thing that loosens somehow…
Anyway, the phone is about to get replaced, either by the newest Fairphone (for ethical reasons), or by a LineageOS-supported second-hand phone (for ecological reasons).
Had similar issues. In my case, disabling HW overlays (always using GPU for screen compositing) in the developer options of Android’s settings has helped a lot. Has to be done again after each reboot, though.