Shader Bug when Clearing Layer - Only happens on Landscapes smaller than 2k.

Hello, I encountered this visual glitch.

I use the exact same Landscape Material. I apply the Automatic Layer to the Landscape. I then apply a paint layer onto the Landscape.

When I do this on a Landscape under 2k in size, I get this blurred patch where the Roughness looks like it is set to 0.

When I do this on a Landscape 2k or over in size, no problemo.

The problem goes away if I close and reopen the project, but obviously this is a retarded way to work so if anyone can offer any solutions may the gods smile upon you.

First 3 screens are from a 2k landscape, last 3 are from a 241x241.