Answer
Some operational reports are purely XML-based and never write into a permanent report result table at all — a few older/generic reports render straight to XML (sometimes via a temporary table used only to assemble multi-transaction output) without ever populating a dedicated Report Table or the shared generic report view. If that's the case for your report, there's no result-key-based row to query; your only option is parsing the archived XML itself, which most reports don't require but a few legacy ones do.