Ok, I was going to take a look, but this is UE4, right?
All you need in UE5, is this
I don’t understand why there is a timeline to fade the sun and skylight, but also an event to turn them on and off? I do also see a lot of people complaining it doesn’t work correctly in the comments.
You could get a copy of good sky, it works with UE4 and does this all for you, I think…
https://www.unrealengine.com/marketplace/en-US/product/good-sky