Didn't change the google_product_category

Using Feed Manager plugin, the google_product_category does not seem to change.
I tried changing google_product_category field name to Category Name and to Category Breadcrumb but nothing changes. I also tried changing the CategoryMap on the Product Filter tab, and tried changing Default Values for Google Product Taxonomy and Category of the Item. None of these made a difference.  Can you please help me? Thank you!

I think you saw the feed file from browser's cache.
Clear the browser's cache and try to check the feed file again.