I think category selection works only if,
– meta applied to ONE TOP category AND
– user select only that category
All other cases, it wont work.
Error message: Some of your fields has duplicated data names, please fix it
And I find that product has as many duplicate meta as its categories.
Even if I select only one SUB CATEGORY, it will make duplicate meta for all its top categories.
Can you please make it to work with multiple categories, whether they are top categories or sub categories?