Editing Metahumans demo file

Hi all,

I’m going to premise this with saying I’m very new to UE4 and am exploring it’s capabilities on a basic level, specifically the lighting systems involved.

I’ve got the metahumans demo file and can see there are some lights used in the scene. If I try to edit the look of these lights (changing intensities, colour) they get reset when I hit the play button. What is it that resets these and how can I disable it?