Plugin incompatibility: Shiptastic

Hello there,

I am reaching out regarding a language loading issue with the Shiptastic plugin when used alongside Polylang Pro and Polylang for WooCommerce.

Customer emails generated by Shiptastic and the Shiptastic admin interface are currently displaying in English, even though the entire website, WordPress site language, and admin user profiles are configured to standard German (de_DE). It does not matter if I select German, English or all languages (via your button in the admin bar) in the admin area.

This issue started a while ago; previously, everything rendered correctly in German. All other areas of the site and all standard WooCommerce emails continue to display in German without any issues.

I have already performed several tests to isolate the root cause:

• Language Settings: Confirmed that both the main site language and my user profile language are explicitly set to standard German (no formal, Swiss, or Austrian variants).
• Cross-site Comparison: On a separate website that does not use Polylang, Shiptastic works flawlessly in German.
• Staging Test & Conflict Isolation: I cloned the site to a staging environment for testing. Deactivating both Polylang Pro and Polylang for WooCommerce immediately resolves the issue, restoring Shiptastic’s emails and admin area to German.

It appears there is an interaction issue between Polylang’s translation/locale loading and Shiptastic’s text domain.

What steps can I take to troubleshoot this further or fix the language fallback? Would specific logging or debug hooks help pinpoint where the text domain loading is being bypassed?

Kind regards,

Florian