I may be wrong but it is my recollection that report URLs that render a result such as:
used to have a Wikidata Query Service link in the bottom left corner of the results which, if followed, took one back to the WDQS report interface and showed the SPARQL used to create the report.
Currently that link takes the user back to a blank WDQS interface.
So.
Click on Wikidata Query Service link in the bottom left corner of a rendered results page...
Expected: I get to see the SPARQL
Actual: I get a blank WDQS screen