When opening the page-editor, the authorLocale is set on the I18NAuthoringSupport, so that form dialogs open directly in the same locale.

However, the I18NAuthoringSupport is a singleton (per-instance) configured component, which means concurrent authors may override the authorLocale from one another, e.g.:

• superuser edits /demo-project in English.
• eric edits /demo-project/about and switches to German.
• superuser opens a dialog; she gets it in German instead of English.

This was introduced in 5.2.3 with MGNLUI-2696.

Couple options:

• Either I18NAuthoringSupport should remain stateless and such synchronization of locale between editor and dialog should be performed differently (privileged option).
• Either I18NAuthoringSupport should be a session or even sub-app singleton.