I dropped my Fairphone 3+ from a height of about one meter. It does not have any visible damage, but the back camera and the pocket lamp no lomger work.
No lomger work mean: in the camera app I can no longer switch to the back camera and in the menu the button to activate the pocket lamp is greyed out and can’t be activated.
After the fall the screen remained black and I had to disassemble and reassemble the screen.
I suppose you’ve also tried to reassemble your camera module?
Maybe there’s a fairphoneangel near you who might possibly help out with another camera module for checking if your one is broken and a replacement might help?
If you reassemble the camera in your FP3+, bear in mind its connector has two connector ends – sometimes the one that you don’t see instantly (it’s under the metal plate) gets disconnected, too.