You created a product feed for Google’s Merchant Center as you want to start promoting your products in Google Shopping only to find out that Google has disapproved (some of) your products because of an issue with your ‘availability’ field. You seem to have added products that have an availability that says “on backorder” (which is a WooCommerce stock status value):
Unfortunately Google doesn’t accept the availability status “On backorder”. Only the values “in stock”, “out of stock” and “preorder” are allowed for your products.
That is why you need to decide what to do with those products. If you want to keep advertising on them (even though you cannot ship them yet to your consumers) than we advise on creating a rule that automatically changes all “On backorder” values to “in stock”.
You can do so by creating the following rule:
Make sure to (manually) refresh your product feed and refetch your product feed in Google’s Merchant Center so Google sees the new availability values.
Don’t hesitate to reach out to our support-team when you need help with the above rule.