Strange Lighting Errors - Need an Urgent Fix

So this is happening on some Modular road meshes I’m creating, its not the lightmaps but I think it has something to do with the normals, the problem does not occur when I have a mesh without a normal map applied.
The lighting affects certain sections of the mesh in different ways, when I created the mesh I was altering one modular paving block to make different variations of road sections.

Changed Lighting

Your lightmap resolution is too low