Last item on the list doesnt show elements from MAP

I created a Image List Item Component from Product data variable and added CategoryName from Category data variable linking to Product.CategoryId using MAP and SET_KEY and assign the same to the Repeat with property using formula:

MAP(Product, SET_KEY(item, “CategoryName”, FIND_BY_KEY(ProductCategory, “id”, item.CategoryId)))

results:

Product Name. Category Name
Fruit Tea Apple 12oz. Fruit Tea
Milk Tea Taro 12oz. Milk Tea
Milk Tea Taro 16oz.

Issue: Category Name is blank in the last item of the list.

are my formula wrong?