Hello @buildinghome,
Please get in touch with your third-party plugin author.
Maybe they have a solution that we are not aware of.
However, here are some steps to troubleshooting:
1. Checkout Page Language Assignment: Ensure WooCommerce pages have been set in all languages. Also, confirm that the checkout page is translated and configured correctly.
2. Permalinks Settings: Ensure that the permalinks for both languages are set correctly. Go to Settings > Permalinks and confirm that the permalinks for both English and German are set up correctly.
3. Language Settings in Polylang: Check the language settings in Polylang. Navigate to “Languages” in your WordPress dashboard. Ensure you’ve assigned each language’s correct language code and URL prefix.
4. WooCommerce Language Settings: In WooCommerce, go to WooCommerce > Settings. Check the “General” tab and verify that you have set the correct location and currency for each language.
5. Cache and Plugin Conflicts: Clear any cache you might have (including browser cache) and temporarily turn off caching plugins to check if they are causing the issue. Similarly, turn off any other plugins that might conflict with WooCommerce or Polylang and see if the problem persists.
I hope it helps.
Best Regards