Why are one of my products no longer showing in my reference field?

If you are suddenly experiencing that one or more of your products is missing from your reference field value, it is likely because their handle in your store has recently been changed.

The underlying metafield value of product reference fields is the selected object's handles. Therefore, when the referenced handles are changed it creates a mismatch between the stored value and the actual value in your store, which ACF is unable to see.

If a mismatch is detected, you will see the following message in the editor:

To remedy this, simply reselect the products in the reference field and click "Save", then ACF will update the stored handle to the new one.

Alternatively, you can also manually update the handle via the Import custom field valuesfunctionality.