And you’re seeing the language changing back to English when you query the customer after making an order? This does sound strange, and could be a bug with Shopify. Have you contacted support yet?
Topic summary
Main issue: After setting a Shopify customer’s locale (language) to Japanese via the API (customer.locale(“ja”)), creating an order for that customer via the API causes the customer’s language to revert to English, leading to shipping emails being sent in English.
Context: Customer and order are both created through the API, not by the customer. Querying the customer after order creation confirms the language change back to English.
Technical note: “Locale” refers to the customer’s language setting used for communications/notifications.
Assessment: This behavior appears unexpected and may indicate a Shopify bug affecting locale persistence when orders are created via the API.
Requested details: The poster asks what information is needed to investigate further (e.g., API endpoints used, request/response payloads, timestamps, store default locale, notification template settings).
Status: No contact with Shopify support yet; no workaround or fix provided. The discussion remains open with a suggestion to reach out to Shopify support for investigation.