My Fairphone 2 turns out randomly.
I’ve already read about that problem and hope It’ll be fixed soon.
BUT my phone also randomly shuts down apps and its system (“System UI wurde beendet”)… Most of the apps it closes are google apps (Chrome, Maps,…). And Maps doesn’t work at all. I can’t use it for more than maybe 5 minutes and then the phone shuts down again.
Then the display does not turn on again after calls so if people don’t end calls, I’m forced to take out the battery to fix it again…
In the topic I linked to, someone solved it by just taking the screen off and putting it back on again. It doesn’t work for everybody, though.
If the problem persists (especially the very frequent system UI crashes), it’s best to contact support. They’ll probably recommend a factory reset at some point, so make sure that you have backups from which you can recover your data.
If Fairphone support can’t solve it from a distance (for example because they think it could be a hardware problem), they’ll arrange for the phone to be picked up so their repairs partner can check it out and/or replace the phone. So your best option is filing a support ticket (or calling them) if you haven done so already.