There is a bug with the Horizon theme (v 1.0.1) where app blocks inside of the new blocks/product-card.liquid are receiving the wrong product, rather than the closest product displayed in the grid.
To reproduce this:
Add an app block that includes a “product” type setting inside of the Product card block. I’m using my Flair badges block to demonstrate this:
The Flair app block is using block.settings.product to access the product, and in this case all grid items are being passed the first product “Ectoplasm 2.0” in this example: