Hi @Moin, sorry for the long delay in our response while we were looking into this.
The Search Banner component came with built-in translations for many languages (German, Spanish, French, Chinese, etc.) in its locale files. These weren’t stored as TranslationOverrides in the database - they were part of the component itself. The migration script from Search Banner → Welcome Banner only migrates translation overrides (custom site texts that admins have explicitly set), not the theme component’s built-in translations, which is what you were seeing here:
I’m sorry for the oversight on our part and that this made migration less smooth!