When I am logged in on the wikibase registry, and click on the link https://wikibase-registry-query.wmflabs.org/embed.html#SELECT%20%3Fitem%20%3FitemLabel%20%3Ffeature%20%3FfeatureLabel%20%3Fneed%20%3FneedLabel%0AWHERE%0A%7B%0A%20%20%20%20%3Fitem%20wdt%3AP11%20%3Fclass.%0A%20%20%20%20VALUES%20%3Fclass%20%7Bwd%3AQ62%20wd%3AQ20%7D%0A%09SERVICE%20wikibase%3Alabel%20%7B%20bd%3AserviceParam%20wikibase%3Alanguage%20%22%5BAUTO_LANGUAGE%5D%2Cen%22%20%7D%0A%20%20%20%20%3Fitem%20wdt%3AP18%20%3Fneed%0A%7D%0ALIMIT%20100
I end up with query results http://..... (not https). When clicking on it, I end up on http://..... and I am logged out. I don't think this is appropriate.
This is a frequent problem with new wikibase installs.