Hello There!
We have a problem with the foliage lightning when using foliage tool, here is a video that shows what happen: UE4 Foliage Illumination Error At NightTime [ Help ] - YouTube
As you can see, the foliage from ona moment to other, starts lightning up, at the point that starts bright, we try a lot of stuff and nothing works, like disable the Emissive from the materials (Emissive = 0) but nothing works.
At this point, is proper to tell you that we are using two marketplace contents in this scenario:
Ultra Dynamic Sky: Ultra Dynamic Sky in Blueprints - UE Marketplace
Trees: Beech tree: Trees: Beech tree in Props - UE Marketplace
We dont know if its caused by a matorial from the Trees Pack, is a very complex Material, but seem to be good.
We will keep an eye here, if you need anything, tell us, we will provide the data for you.
Whitman And Olbert
PD: Maybe the video is still not upload, dont worry, the video is uploading right now