The tooltip displayed on wd:P518 is wrong.
1/ Go to https://query.wikidata.org/
2/ Copy and paste this SPARQL query:
SELECT ?item ?itemLabel ?prop ?propLabel ?rank ?value WHERE { ?item p:P1971 [ ?pq ?value; wikibase:rank ?rank ] . ?prop wikibase:qualifier ?pq . FILTER( ?prop IN ( wd:P518 ) ) . } LIMIT 100
(a special case, with wd: for a property, because it's a qualifier)
3/ With your trackpad, go to the text wd:P518
Expected : Display a tooltip of property P518
Now : A tooltip is displayed with title of Q18055686
Note: My language used in Wikidata Query Service tool : French (fr), but the issue is the same with English