By testing the various included presets I found that some sequences have this behavior at dawn, but never both dawn AND dusk, just one or the other. Any pointers to how to work around this would be great, as I’m finding it hard to create a continuous time of day cycle.
Upon further testing: seems the cloudiness parameter worsen or lessen the effect, the more clouds the worse the effect. When the Sun lights the clouds from an horizontal or below angle (sunrise/sunset), it turns them completely yellow or orange. Then the skylight samples this overall sky color and fills the world below. Seems like a solution would be to limit the clouds being colored at sunset/sunrise just around the sun position (just like it happens in real life), instead of coloring all existing clouds. Sort of like simulating the earth’s curvature.