I’m having a similar issue, thought perhaps the opposite as the original OP, with the way UE displays Vulkan preview in relation to the way it builds.
Using the default VR template, no changes other than ticking Settings > Preview Rendering Level > Android Vulkan.
As seen in attached images, the editor displays Vulkan with a bit less contrast, greyer blacks. Much as it is rendered when built to headset (shown in the middle frame of the second attached image).
But when Played using VR Preview, Vulkan is much much darker. Far darker than it is actual rendered when built to headset. It is so dark that it isn’t even a usable preview in my personal level because I don’t have as much bright sky as this template.
Is this expected behavior? Am I missing something @VictorLerp ??