No Spanish translation of "Unblocking..." in Greeter despite translation in PO file

When trying to unlock a persistence in Tails 3.10.1 in Spanish the temporary button displays “Unlocking…” instead of the translation in the PO files (“Desbloqueando…”). When the passphrase is wrong, the button goes back to “Unlock” (in English) even though the original button is translated correctly (“Desbloquear”).

The same happens for German at least.

Related issues

Is duplicate of #13438 (closed)

Original created by @sajolida on 16278 (Redmine)

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