You can check for inactive accounts you may be following with this: https://yeghro.site/nostr-inactive-users-checker/ and unfollow them if you like.
very useful tool to help prune your following list if you're getting close to that 1k following count where things start getting weird nostr:note15pwpj72utm3pd28cy0dsl0j4asqkey5ysmvds7lc8rz8ztrp8hws3ja2mz