[Tracker] Searching with 'tracker search' or tracker-needle does not yield results

[Stefan <tracker-list fry fastmail com>]

Hi everyone,

I am having issues with tracker search. It does not yield results even
though it apparently indexed files.
See this example:

$ tracker search -f
Files:
  file:///home/user/temp/formalcharge.pdf

$ tracker search formalcharge
Results:

$

Am I getting the syntax for search wrong? Search does not work with
tracker-needle or from within Gnome Activities either. 
Any advice on how to debug this? I had journalctl -f running but there
was no message logged.

Best regards,
Stefan