Spotty lightmaps

[Warner_V (Warner)]

So I’m having this weird issue in UE4.26:

Light baking results in some (very few) objects to be full of spots… a little like you would expect if the wrong lightmap is loaded. Only it’s not the wrong lightmap that is loaded…

The project was migrated several times so maybe it’s connected to that… I don’t know. If I use the objects in a fresh map, the issue disappears. But if I move all objects to a new map (move to a new sub-level, then load that one and bake lighting) the issue stays. Creating new lightmaps (with a lower or higher res) doesn’t change anyhing.

I’m completely at a loss and I’ve spent two days on this already.

Please, please… Who can point me in the right direction??

Here’s an image of the spotty-ness:

[Warner_V (Warner)]

So finally I found the issue, and it’s something that I would have never expected…

I attempted to smooth out the baked lighting (hoping to reduce such artifacts) by setting in World Settings:

Indirect Lighting Smoothness 3

While this is in fact causing or enhancing the issue. Instead, the problem completely goes away when setting

Indirect Lighting Smoothness 0.5

Hope it helps someone!