I would encourage everyone who has this problem to contact support. Fairphone is very well aware of this problem. It is one of the major problems with the FP2. We want to show off our phones as well working devices so that more people can join the movement for fairer electronics. If fair electronics equals mal functioning electronics, it will be a loosing battle.
I’m now on my third phone and it works really well. I’ve had two phones that I’ve sent in with problems of random reboots. FP2 is not supposed to have random reboots. It is supposed to work with 4G. It is supposed to be stable. We are supposed to be able to recommend Fairphone to everyone without being afraid that they will get a phone that reboots all the time.
Support has gotten faster and better than it was a year ago. And, I hope that the quality control at the factory has gotten better too. I think it is mainly a hardware problem. I run the same apps on the phone that I have now as I did on the two previous phones.