I dug into this one more and found the culprit. The Store Exporter Deluxe plugin adds a “attribute_escape” filter, which ends up overriding the esc_attr call that ACF makes when it outputs the value of a field. The filter specifically removes the equals symbol from the value, which explains why we’re getting an empty string for the “is equals to” value. This filter is applied in the /plugins/woocommerce-store-exporter-deluxe/includes/formatting.php file. I commented out the filter for now and ACF is back to working as expected. I’ll reach out to the other developer to see if he can clean up this issue, though maybe there’s something that ACF can do to prevent other plugins from overriding the esc attributes like this.
