DEL command does not entirely remove the document from index

I tried deleting multiple documents from redis index using “DEL” command.
It does not entirely remove the document.

(empty array)

1624551190413 is one of the documents I deleted. Though the content is deleted, the title still exists. Thus the number of documents in the index does not change even after deletion. How can one remove this totally?

FT.DEL deletes the entire document. It does not return (empty array) message. The count is also reduced properly. But FT.DEL does not allow multi key deletion.