Question What is going on with my emmisive materials here?

I am hoping someone here can shed a little light on the 2 attached light baked screenshots. The 1st image with the glow of the letters is how it should look, but it keeps changing to the 2nd image where the glow is not even and way less glowing. I am stumped as to what is causing this as it has happened a few times now and the only way to solve is to go back to an older version of my project. In both of these images, everything is the same. Both have the same emissive materials with the exact same properties, with the exact same light bake settings, with the same project settings, in the same version of Unity. Everything around the words is the same material and settings too as well as everything else in the scene. Even if I copy/export/import over the scene from the one that works, it ends up looking the same as the 2nd image. Each time this has happened I was not editing this scene all so I am unclear why it is fine one moment, and then like the second screenshot the next and once it happens, it never bakes right again. Just this one emissive area. All the other emissive materials bake consistently fine. It does not matter what version of Unity I use, it will not bake like the 1st image once it messes up. It is driving me crazy as I cannot see any differences, even when I text compare the YAML of the scene file. I am hoping someone here may have some insights as to what may be going on.

 

I discovered that baking with the deprecated Elnlighten fixes this issue, with all other settings the same versus Progressive GPU. Why?