Trigger Volume not working on iOS device

Hi, I’ve set up a simple trigger volume to change the color of a light from green to blue. It works perfectly in the Editor, but the trigger is not triggered when I run the app on my iPhone5. I’ve added a simple basic cube to the scene, and that shows up in the editor and on the device, so I know that the changes made in the editor are updated on the device. It’s just the darn trigger not firing. The trigger is setup as a level blueprint, and I’ve compiled the blueprint.

Any help – I’m new to UE4, so I could be doing something wrong… :frowning:

The light itself is setup as a ‘stationary’ light - according to the tool-tip in the editor, the light is baked in, but it is still able to change its color. Maybe it’s something to do with my device settings???