Steps to reproduce:
1) Open the attached project.
2) Open scene 'Normal Maps'.
3) Focus the scene camera on the group of cubes in the scene so that they are viewed from a low angle (see picture).

- There are 3 sets of 3 cubes in the scene - 3 without normal maps, 3 with generated normal maps and 3 with imported normal maps, all arranged in lines.
- Notice the seams/different colouring between the cubes.

Note: rotating the different cubes by 90 degrees around any of the axes makes the seams invisible.