Hello,
The unfollowers service is still “alive”, but changes to the API’s on Twitch’s side have caused quite a few problems.
More specifically, the problem with your account was that none of the official bots (wizebot, kikettebot, wzbot) had a moderator rank, and for some actions Twitch requires it (even if you use a custom name).
However, the problem has been overcome, and your list is now up to date again 