A product listing with or without other sellers has “Amazon Fresh” selling on the Amazon website, but PC2 does not detect it.
TL;DR: Regrettably there is no current solution to this problem. Unless and until Amazon policy on this matter changes, there is no way to obtain information about the Amazon Fresh offer.
We have queried this issue with Amazon, and this was their response:
This is Anthony again from the Developer Services support team. I heard back from engineering and they were able to confirm this is working as intended it seems. The API will automatically and always omit offers from Amazon Fresh from this API. I will be reaching out to our documentation team to add a footnote, or FAQ about this use-case as this would be something that might arise again and thank you for helping us pin-point this down. We appreciate your patience on hearing back from us on this, and I hope you have a great rest of the week.
When it was put to them that this impacts on our users' decision making ability on affected listing, they responded:
Amazon Fresh is a separate line of business, basically with its own marketplace ID, separate from Amazon Marketplace. They manage a private catalog of Vendors for which they honor different contracts.
Amazon Fresh, as well as Amazon Go, offers items listed only by selected vendors who signed a contact with Amazon, which allows them to sell national and local brands plus high-quality produce, meat, and seafood. These type of items are not sold by Sellers on the Amazon Marketplace.
We have informed our product management team of your feedback. Thank you for taking time to outline this limitation and it's impact on your business. Your feedback helps us make continuous improvements that benefit all of our costumers.