Texture Atlas issues

Hello all!

Firstly, thank you for taking the time to read my post.

I have imported an FBX from 3ds Max into Substance Painter. I have added a pre generated Texture Atlas (Base Colours only) to a Fill layer, unfortunately certain objects within the model display the incorrect colour, in 3ds Max all objects display the correct colours.

• Attached you can see the implemented Albedo (Atlas_Albedo). This texture consists also of many 4x4 pxl colours top left.
• Magnified image of the Albedo 4x4 coloured blocks.
• Exported UV image from 3ds Max (for reference only, UV's within FBX are used).
• Substance Painter Fill options (Painter_Fill_Options), no transformations added to Fill layer.

Doe anyone have any idea why certain objects display the incorrect colours? Or rather, why the colours dont match exactly? Unfortunately I am unable to provide the 3ds Max or Substance painter files. 

Substance Painter Version 7.4.2 Build 1551

Cheers