Hello,
As a test, can you try enabling “r.SkyLight.RealTimeReflectionCapture” after the cutscene plays, in both cases? If this helps, you could add this to your project’s Scalability ini as an override.
It is possible that the Skylight’s cubemap it out of date.
Is your scene meant to be used without Lumen? You can override the scalability inis to make sure Lumen is always on.