how long before post indexer indexes posts?

I have about 20 or so posts across 6 sites – just installed and network activated post indexer.

In the Post Indexer settings it doesn’t show any posts that it has indexed.

The rebuild queue status has six sites in queue, 0 site being processed, 6 sites awaiting processing and 0 sites will complete processing on next pass.

Do I need to setup or switch something to have posts indexed?

the site is