title: Unreal Engine: Area becomes lit after building the project, without any actual lighting
body: <p>I'm currently learning UE4 basis from the Unreal Engine YouTube channel.
  In this particular blueprint tutorial a Trigger Box is used so that whenever an actor goes inside a small room, a PointLight is lit after 0.5 secs delay. 
  As long as I DON'T build the project, everything works just fine: the room is pitch dark, I go inside, light turns on, I go outside, light turns off. But after building the project the whole room is slightly lit for no reason. 
  The PointLight blueprint script still works, but the room isn't dark anymore. I literally followed step by step the video (and actually you can notice he never builds the project) <a href="https://www.youtube.com/watch?v=gHdwOiR0D0A&amp;list=PLZlv_N0_O1gY35ezlSQn1sWOGfh4C7ewO&amp;index=3" rel="nofollow noreferrer">This is the video I'm talking about</a></p>
  
  <p>The only way I have to make it work properly again is to delete the PointLight Actor, build the lightning, create a new PointLight Actor, add it to the Blueprint Script and NOT build the project.</p>