When Turning Nanite on with a mesh that is using a basic Diff / Packed ORM / Norm - the diffuse gets some kind of overlay/adjustment made to it, causing it to appear brighter. (Unlit Debug Mode)
Has anyone else come across this issue? I seem to be able to repro it 100% on Ue5 Release.
not 100% sure of the reason this is happening, but it might have something to do with the nanite/lumen interaction. could be worth checking if your base color is also being adjusted. in the images you shared, i can barely see a difference, is it quite obvious in Lit mode too?