This came up in T6115 (https://dev.gnupg.org/T6115#173267 and following):
If a certification is already revoked it appears in Kleopatra as if a revocation happens anyway:
If it is not possible to recognize this before starting the revocation process (as discussed in the origin ticket) there should at least be no confirmation of the revocation which did not happen (again) or even an error message.
Probable cause: gpg status code is missing