It could have been offline for a bit and that combined with the disruption we had a few weeks ago could have caused scheduled removal. Unfortunately I cannot track this back any more. As for the IP searching: if you search solely on the IP and it's not in the server list yet, you will not find it. If you would (have) typed the ip:port, and the server was/is not in the list yet, it would come up for a page to have a suggestion to add the server.
Regards,
Paul