My fp3 reboots itself out of the blue

[OldRoutard]

Hi and welcome to the community forum.

You might have a look at this topic which sounds similar:

Unexpected reboots and dual SIMs

Hi all, I bought my FP3 for Christmas 2020 and since the beginning I had a problem of unexpected reboots (around 5-6 times a week). I opened a ticket but after three months and a half of testing (and one pit stop in the Fairphone technical lab) I realised the problem depends on having two SIMs in the phone. There is another topic similar to this in: https://forum.fairphone.com/t/fp2-reboot-due-to-dual-sim-cards/28608 but it’s closed and it relates to FP2. I’ve tried many combination of SIM…

A work-around is suggested in post #3 : set the preferred network type of SIM 2 to 3G only. This might not be an option in your area, depending on your network operator’s policy.