Unique visitors show only on a day report

I’m only getting the ‘unique visitors’ stats on a report for a single day. If I try any other ammount of days (range of days, week, month) then unique visitors shows a zero value.
Not sure if this has anyting to do with the 1.6 upgrade, but I discovered this issue just minutes after upgrading. I did a re-install, but kept the existing tables because I needed the report for last month. Hosting in Dreamhost.
Thanks for your time.

It should work for weeks and month. It is disabled for Years and date ranges. see How to - Analytics Platform - Matomo