I’m struck by this issue either.
Today my FP3 (no FP3+) fall down and the screen flickered for a few seconds and then the display was black.
I hope after disassembling and cleaning the contacts everything will work again.
Wish me luck…
I have the same flickering issue with my FP3+
It started after I got the phone for 2 months, I didn’t drop it.
The screen sometimes will flicker for a few seconds, and then back to normal.
I can still use it, it’s just that random flickering a few times a week.
I’ll try opening it up and secure the connector.
I realised that sometimes the flickering can be caused by slight bending of the phone.
For instance, getting in or out of the phone case. The original case by Fairphone is very rigid, getting the phone out of the case needs to apply some force. My phone can flicker when I’m doing this.