Instance Static Mesh lighting problem

So yea sometimes my ceiling that I create from the Instance Static Mesh can be seen in the dark(I spawn them from BP, they spawn in groups of 100), I guess its lighting does not build, its root is static and it is static itself so I not so sure whats going on here O-o.
Thanks for any help.

-_- moving the level, 1 meter to the ground fix the problem… Black Magic!