Incorrect lighting on textures (pics inside)

So I have this trench wall with a lantern on it. The first picture shows how it is supposed to be (more or less). However when I zoom out I get the bottom picture. Same thing I get inside the game. This trench are two different meshes that are not connected to each other (I tried to parent them but didn't help) the pole in the middle is just to hide the connection. Any help appreciated.