Whitelisting blocked user doesn’t work

A friend tried to comment on my site and got “You have been flagged as spam/malicious.” The logo shows “failed disallowed_list.”

When I click on the IP from the log, it goes to the IP Blacklist Check site and says “Good news! [ IP ] hasn’t been reported to the Zero Spam’s blacklist.:”

I whitelisted his IP. He tried again and got the same error.