"Make new translation of this page" can create invalid page translations
Since #81345 the Make new translation of this page feature within the page module directly creates localizations instead of opening the edit view for page translations.
This can lead to invalid page translations if e.g. the
title has been configured to be empty in translations (unset
l10n_mode) and thus must be filled by editors explicitly. In this case the edit view is shown correctly with errors after localization but one can simply close the view without additional prompt or action. After this the translation exists without title which in itself can lead to further issues. When trying to save instead a proper dialog is shown mentioning the invalid fields.