Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
One of the large containers was cracked and the process to return it via Amazon became an impossible task, especially from Australia. It's easier to buy something on Amazon, but an absolute pain in the neck to return or report an issue. You need to fix this Amazon !