Hello,
I think there might be a bug with the 4.18.1 version of UE.
When I create a level (File>New Level>Default), built it by clicking on ‘Build’ and save it, everything looks to be fine, no particular error message or whatever.
But if I load an another level, for example the Minimal Default Map (in the content browser) and then comeback on the created level, the level needs to be re-built, the light hasn’t change but in the shadowy part of the map I see the ‘Preview’ watermark.
Breaking News: It doesn’t happen if I close and re-open my project.
So my problem seems way less important now so I’ll just post this message for the Unreal Engine Staff just in case and for those who might have the same problem.
Thanks for reading.