When modifying the properties of a Skylight actor as a component within Blueprints, the changes are not reflected in the Blueprint viewport.
If you drag the blueprint into an empty scene and modify the Skylight's intensity, you can see the effects in real-time in the main viewport, but this behavior does not persist while in Blueprints.
I tested this in 4.11.2, 4.12.5, and 4.13 and the issue occurs in all three engine versions.
1. Download and Open attached project.
2. Open the Skylight_Blueprint.
3. Select the Skylight component in the list.
4. With the Viewport tab active, modify the Intensity of the Skylight component.
Outcome The skylights intensity changes are not reflected within the blueprint viewport.
Expected The blueprint viewport renders the changes made to the Skylight's intensity.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-36426 in the post.