Qt WebEngine starts renderer processes with the --lang option for passing the actual QLocale setting. Thus already running processes are not expected use a new locale set in runtime. However, processes started after the locale setting should use the new locale. Qt WebEngine pass the appropriate --lang option for the new renderer process but the ResourceBundle instance doesn't get updated.

The problem is demonstrated by the attached example. The second WebEngineView instance (viewEN) is created after a locale setting thus should set English error message in the view title. Instead of that it still set Hungarian error message.

This problem can be reproduced on Linux only.