City Sample map - added object popping in PIE & Sequencer

I am experimenting with adding object to an existing map - in this case adding meshes from Mission to Minerva into City Sample Map (I am using 5.1)

The objects behave inconsistently in the sequencer and PIE, though in the editor itself they are fine. The Cargo Ship Blueprints only pop in when the camera gets close. I altered the blueprint of the ships in the picture below (and, as you can see, played with the materials) but the landing pad, from the same package is untouched (apart from the materials) and appears at all distances - what is the difference and how can I get the cargo ship appearing at all distances?