No, I've not defederated from that instance. Click the "Instances" link at the bottom of any page to see the instances list, those blocked/defederated are on the right hand side.
If you've only searched once, its possible you are the first. Try again after ~30 seconds, but also change the search dropdown from "all" to "communities". For some reason the default search type changed in 0.18 to "all".