Fulfill button gone for Amazon FBA

[TSouls]

We have been using Amazon FBA to fulfill orders. It has been working beautifully until last Thursday. Suddenly the Fulfill button vanished from the order pages. We have a ticket that was supposedly escalated to Shopify technical support on Friday, and marked as urgent as we can't fulfill orders, but they are not getting back to us. I tried myself deactivating and re-activating the Amazon FBA service. No joy. Also verified Amazon settings are correct. We have made no changes in Shopify (or Amazon) recently, and it was working fine as recently as early last week.

Is/has anyone else experienced this issue? If so, was it resolved, and how. Thank you!

[JoesIdeas]

I wonder if this is a problem at the product level... I'm thinking that if the fulfill button isn't showing on an order, it might mean the product has "this is a physical product" unchecked in the product page.

If fulfill is showing but then fulfill with amazon marketplace web button isn't showing, I would look into the product page as well to make sure it's still showing inventory managed by amazon marketplace web.

If neither of those work and you want some help, I can send a collaborator request to take a quick look for you to make sure everything is connected correctly (I do a lot of work with FBA and Shopify).

My best guess without seeing is it's a setting on the product level.

[TSouls]

Thank you for your reply. Really appreciate you taking the time.

Not only has this been working perfectly for many months, and as recently
as last Monday, we have made no changes to the products or product pages.
Plus we reviewed all those settings ourselves anyways, before contacting
Shopify support... and then they reviewed them again themselves, before
escalating the ticket.

So your suggestions are much appreciated, but that's not it unfortunately.
Wish it were that easy. Thanks again!