Longdate localization High Sierra

In my web application I retrieve a date from a PostgreSQL database and display it with Longdate. Until before upgrading from Mac OS Sierra to High Sierra, this date was displayed in Spanish. Now after the upgrade, it is displayed in English. My language and region settings have not changed. They are still Spanish Panama. Any clues?

Web apps get the localization code from the browser. If that changed and there’s no longer a matching value, you’ll get the default value.

If you want to check what the browser is sending, just put Session.LanguageCode into a label or TextField.

Thanks for your answer.
Session.LanguageCode = es
But Longdate shows Monday, September 25, 2017 instead of Lunes, Septiembre 25, 2017

Oh right, sorry. The strings shown from the Date methods are generated based on the configuration of the machine where the app is actually running (the server). Please make sure it is also still set to the correct language.

It is running in my own computer. Not yet built or deployed. This behavior started on High Sierra upgrade.

Well, the best thing I can suggest is to file a bug report and include specifics about how your system is configured in terms of language.