Issue

Constellation applications are not localized if users are using browser Locale or pxRequestor.pxReqLocale. 

Symptoms and Impact

Constellation localization is not triggered if the operator locale is not defined on the Operator ID record, and the user relies exclusively on the browser locale. 

This behavior differs from the traditional UI, where localization can be invoked purely based on the browser locale without requiring an explicit operator locale.  

This discrepancy can lead to confusion, particularly in environments where operator locales are intentionally not set, and localization is expected to follow browser settings. In some cases, developers may observe partial localization when working in a localized version of Dev Studio.  

Steps to Reproduce

1. The locale in operator id is empty. 
2. Change browser language to any language other than English. The application is not translated. 

Root Cause

This is a product feature gap. 

Constellation localization logic does not fall back to the browser locale. It relies exclusively on the locale defined on the Operator ID record. Unlike the traditional UI, there is no mechanism to automatically derive localization from the browser when the operator locale is not configured. 

Solution

This issue has been resolved in Pega Infinity™ '25.1.3 and Pega Infinity ‘26.1. 

 This has been resolved by implementing a proper locale determination hierarchy where Constellation portals now follow the priority order of Operator locale → Browser locale → Default locale, ensuring that language bundles are correctly loaded in environment info for browser locale scenarios.

References

Internationalization and localization 

Creating a new operator ID