Delete duplicate SKUs and bulk clone the whole SKU group at once
Remove duplicate SKUs under one code and clone the entire group of all SKUs in one go.
When duplicate SKUs appear under one code, delete all of them and add them again from the warehouse.
Clone the entire group of all SKUs at once rather than cloning items individually, since it is difficult to identify which duplicate is which.
A reference video can be used to understand how to bulk clone.