Random Map doesn't want spawn in Clients

Hey, I am making a multiplayer game. I have an issue with MapCreattor gameObject. It has NetworkIdentity component attached, in which ServerOnly is checked in. In my script, in the OnStartServer() method, a map is created. Map consists of several Planes, that are prefabs. These planes also have prefab children. In Start() method, plane is created, along with random child prefabs spawned on it, which give it it's randomness.

Summarizing, the quantity and position of planes is constant, but the number of child gameObjects on these planes vary. After I start the game, only host generates the map (theoretically there should be only 1 map) but client can't see it.

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