Sites proxied through Cloudflare resolve to Cloudflare's addresses, so from outside they look as if they have moved. That's why *.ns.cloudflare.com is on the Trusted nameservers list by default: any domain using them always counts as active.
Add your own nameservers in Settings → Trusted nameservers (there's a one-click suggestion for this server's nameservers). Remove Cloudflare from the list if you want accounts that moved hosting but kept Cloudflare DNS to be flagged; proxied sites hosted here would then be flagged too.
