HQ Lightmap Moire pattern artifact in Alpha

I have noticed that all my HQ Lightmaps have this moire pattern in the Alpha. Is this expected in UE4.11? If not, how do I get rid of this artifact? All of my settings are epic and production quality.

I am assuming that this banding is intentional by UE4 but can anyone tell me what it is used for? From a rendering standpoint, I don’t understand how this is created or useful?

Anyone know what the banding portion of the Lightmap is used for in UE4? Is it filtered in the engine to provide additional light? Why is this information necessary?