For anyone else coming across this thread who is troubleshooting their product feeds, there is another possible cause for not seeing products in preview.
If you :
- know you have the correct collection selected
- you are able to see individual product blocks but not product feeds in the preview
- you have products in stock and are not using a third-party app to track your stock
and you’re still not seeing your products load within your product feed, it may be because the product feed hasn’t been associated with the message yet because no messages have been sent.
Try changing the recipient of your campaign to a segment with only you and sending the campaign to see if the blocks load correctly. If you’re editing a flow message and cannot change the trigger, set the message to manual. Try to trigger the flow yourself and find your email under Recipients > Needs Review. Send the message to yourself and open it in your email provider to see if the product feed loaded correctly.
After confirming it has, you can set the flow to live if you wish, and you should be able to see the products load in the product feed when you try to preview your message again in the future.