My newly-installed bi-fold louvered doors don't lay flat

[GracieZG]

My carpenter just installed four sets of bi-fold louvered doors. They are beautiful, but they don't stay flat. They fit (plenty of room on all sides), and they are plumb (I made sure of that!). But the joint in each set of two doors where the hinges are doesn’t stay flat. I can push it flat, but it immediately comes back out about ¾ inch. So the four sets have a slight "accordion" look to them. It seems to be something with the hinge design, I think. Anyone have any experience with this and how to remedy it? They are Relia-Bilt.

[noseall]

Louvre door construction and material make-up (usually pine and ramin), is such that it lends itself to warping very easily.

[GracieZG]

I'm now wondering if there is a way to embed magnets at the hinges that might make the hinge tighter.