Product Attribute not import

We used the WordPress Importer and successfully imported all content but
woocommerce product attributes are not imported. Tried a few different tests, and few different servers. Same result. Any ideas?

Here is an example of an error received after attempting to import:

Failed to import pa_color Blue
Failed to import pa_color Brown
Failed to import pa_size Large
Failed to import pa_size Medium

Any help is much appreciated!

Thanks

https://www.ads-software.com/plugins/wordpress-importer/