Texture Stretched When Exported to GLB

I’m having problems when exporting my sketchup project to GLB. The textures / materials all look fine when I’m inside Sketchup, but when I export and view the GLB one of the textures (the underside - all of the rest of the files are fine!) appears very stretched, and I can’t see how to fix this in Sketchup or what’s causing it. Any tips or advice?
https://www.abbuildingproducts.co.uk/content/video/Cdeck-Silk-Grey.skp
https://www.abbuildingproducts.co.uk/content/video/Cdeck-Silk-Grey.glb