Network objects (with a NetworkIdentity script attached) are spawned at the correct location, but not with the correct rotation and scale. This is simply because the information is not transmitted during spawn. There may be a fix for this in the future.

The rotation of the yellow objects was not synchronized across the network.
The rotation of the yellow objects was not synchronized across the network.

In my opinion that makes sense, because there may be objects that do not even need position, rotation or scale. For this reason, there is already a script called NetworkTransform, which synchronizes the properties of Transforms or Rigidbodies. And it works. However, the rotation is only applied after a short delay, which is noticeable by the player. So, if Unity is going to fix this, I guess the NetworkTransform might be the right place to do it.

In the meantime the problem can be worked around with this little script:

using UnityEngine.Networking;

public class NetworkObject : NetworkBehaviour
{
    public override bool OnSerialize(NetworkWriter writer, bool initialState)
    {
        if (initialState)
        {
            // Transmit the rotation (and scale) only once (initalState)
            writer.Write(transform.localRotation);
            //writer.Write(transform.localScale); // Uncomment this line, if you need scale too
            return true;
        }
        // Don't send further state updates
        return false;
    }

    public override void OnDeserialize(NetworkReader reader, bool initialState)
    {
        if (initialState)
        {
            // Apply the retrieved rotation (and scale)
            transform.localRotation = reader.ReadQuaternion();
            //transform.localScale = reader.ReadVector3(); // Uncomment this line, if you need scale too
        }
    }
}

Just attach the new NetworkObject script in addition to the NetworkIdentity script and it should work:

The rotation of the yellow objects was synchronized across the network.
The rotation of the yellow objects was synchronized across the network.