Steps to reproduce

1. login to admincentral on https://demoauthor.magnolia-cms.com/.magnolia/admincentral
2. open the pages app
3. select the /travel page
4. click on "Add page" action
5. enter a page name, select template "Basic Template" and confirm with "Next" button
6. the "Page properties" dialog opens and shows localised fields like the page title and the language switch in the lower left corner of the dialog (so far everything as expected)
7. cancel the dialog
8. select the /sportstation page in the pages app browser
9. click on "Add page" action
10. enter a page name, select template "Basic Template" and confirm with "Next" button

Expected results

The "Page properties" dialog opens and does not provide a language switch and the fields are not shown to be localized.

Reloading the page and first selecting /sportstation and then /travel will show the "Page properties" dialog for both without language switch and without localized fields.

In the config /server/i18n/authoring@class the MultiSiteI18nAuthoringSupport is configured which should determine the available locales for each site individually.
In the configuration of the sportstation site i18n is disabled which
https://demoauthor.magnolia-cms.com/.magnolia/admincentral#app:configuration:browser;/modules/multisite/config/sites/sportstation/i18n@enabled:treeview:

Actual results

The "Page properties" dialog opens and shows localised fields like the page title and the language switch in the lower left corner of the dialog

Workaround

Reloading the page seems to clear the cached

Development notes

The problem seems to be the info.magnolia.ui.dialog.actions.OpenDialogAction where the value context is populated only once and then cached independent of the node in the valueContext.