We have a few products in our shop on ‘allow backorder’ but they are displaying a message on the image in the shop page. We would expect this message to appear if we had the ‘allow but notify customer’ option selected on the products but we don’t.
It only appears to be doing it on the products that have variations but we haven’t experienced this problem on another site when using variations and allowing backorders.
The products displaying the message can be seen here: https://thecornishmarket.co.uk/product-category/valentines-day/
This is one of the products showing the message: https://thecornishmarket.co.uk/product/gift-for-her-hamper/