Whenever I search something on the newly-created sysop-it.wikipedia wiki, I get:
An error has occurred while searching: We could not complete your search due to a temporary problem. Please try again later.
And I see the following on logstash:
Search backend error during full_text search for 'prova' after 2: index_not_found_exception: no such index
Based on similar tasks (e.g. T234326), my guess is that the search index sysop_itwiki_content was not created by addWiki.