Hello - New guy here looking for some insight - I have the now discontinued 2579512 double french door with the multi-point lock. I have 2 issues with the passive door.
1). After locking this door (pulling up handle to extend the upper and lower "deadbolts" and when closing the active door, if you are not gentle the "bump" of closing the active door will Jar the passive door enough to "Pop" and release the passive door deadbolts!
2). After everything is closer and locked, from the outside you can release the deadbolts of the passive door simply by trying to open it - the "Hooks" will still be attached of course from the active door, but now both doors are free to swing a bit and create a huge loss in the seal.
I thought my kids were always messing with the doors and didn't know how to properly close them - but now I know it's not them. Even if someone Jumped up and down on the floor inside, it might be enough to "Pop" and release the passive door latches.