Custom material offset not working

I have a cedar plank texture that has a heavy horizontal seam each end and when applied to the object, I can stretch the texture but not offset this so that the seam is not showing.
There is no movement at all even if I stretch the texture to a larger size I can see this works fine with D5 materials. Any help would be appreciated.

Hello @vueconcepts

Welcome to D5 forum, and apologies for this issue. Could you share your texture file here so that I can run a test on it?

Thanks