Troubleshooting Customers Seeing Someone Else’s Address @ WooCommerce Checkout

In a recent Business Bloomer Club Slack thread, a developer encountered a complex issue with a WooCommerce site where user address details at checkout were occasionally displaying previous customers’ data.

The issue seemed specific to the default language, Dutch, raising concerns about cache-related problems and potential conflicts with WPML.

Here’s an overview of possible causes, steps to troubleshoot, and a provisional solution that might help if you’re experiencing a similar situation.

Diagnosing the Checkout Address Caching Issue

Caching is often at the root of this problem, especially on eCommerce platforms where dynamic content changes frequently. Here’s a troubleshooting checklist:

Clear and Control Caching Mechanisms

Disable WPML Cache

1. Access the Cache Clear Option: Go to WPML > Support > Troubleshooting, and use the “Clear Cache” option. This can help ensure WPML isn’t storing stale checkout data.

Kinsta Cache and Cloudflare

1. Confirm Page Exclusions: Ensure checkout and cart pages are fully excluded from any server-level or CDN cache to prevent customer data from being cached incorrectly.
2. Disable Caching Temporarily: If possible, turn off Cloudflare or Kinsta caching temporarily to isolate the issue and test if caching is indeed the problem.

Implementing a Temporary Solution

This filter will help prevent pre-filled checkout fields for guest users:

if(!is_user_logged_in()) { // is user logged out?
    add_filter('woocommerce_checkout_get_value','__return_empty_string', 1, 1);
}

This workaround effectively clears the checkout fields for non-logged-in users, helping avoid cached data from other users.

Next Steps

Once the cause is identified, you may want to consult with your hosting provider about implementing a stable, optimized caching setup that respects dynamic WooCommerce content. This approach should prevent accidental data sharing and ensure a secure, accurate checkout experience.