Why won't some products publish to Google despite correct shipping costs?

A number of my products will not publish to Google with an error to add a shipping cost. All shipping costs have been reviewed by shopify and are correct yet still these products remain unpublished. Has anyone else experienced and found a solution to this error?

Some of my products for some reason are published even though all information is exactly the same as the unpublished products. This is greatly affecting our traffic so any insight would be much appreciated!