Not working with Woocommerce CSV Importer

Hi, I’m trying to import some variable products using the csv importer. As a test I set up a variable product and exported using the CSV exporter I can see the fields for the variable product:

Meta:_amb_vap_prod = “yes”
Meta:_amb_vap_prod_cart_text = “Go to store”
Meta:_amb_vap_prod_url = “https://defaulturl.com”

I can also see the field for the variation urls

Meta:_amb_wpvap_variation_url = “https://productpage.com”

If I then delete the product from woocommerce and import using the csv importer, the variation urls import ok, the three field for the variable product don’t.

Please can you advise? Thanks very much.