Sorry Roi, this got a bit lost in the cracks. I guess there must be something wrong with the report code itself? discourse/app/models/concerns/reports/posts.rb at 8596aa34c46071eb42ffbb9e19ad733d1765578e · discourse/discourse · GitHub .
Do you have access to the rails console of your site? If so try this and see if it gives you any data:
Report.find("posts", start_date: 4.weeks.ago, end_date: Time.zone.now).data
This will also output the SQL queries it runs, so might be some further clues there.