Hi Team X,
After several hours of trouble shooting I hope you can see this issue with fresh eyes and perhaps assist. We have tried switching to a default theme, deactivating applicable (and non-applicable) plugins, worked through different user permissions scenarios, different media types, sizes, upload options, nothing seems to explain why 3 cloned products with exactly the same settings, same images, same admin user created... would 2 have a hover variation image display in the grid page below.
It's a serious issue and we're stumped - I will contact the Grid too - but I really hope someone can make sense of this.
Originally the user Shop Manager - thought it was their user permissions but I am having the same results through all the tests above.