filter not applying

[leobg]

I am having a problem with Spent Time plugin - when I go to "spent time" menu, it does not let me change the user and time interval from the topmost menu - the table at the bottom always shows only the logged in user entries for the past 7 days. When I pick different user from the drop down menu and/or change time interval, when I click "Apply" button, I get a momentary "Loading" prompt but the time table entries at the bottom of the screen remain unchanged (current user, last 7 days). I get no errors or anything in log files. I tried with various browser - problem is the same regardless of browser.
I am running Redmine 3.1.1 with Spent time plugin ver. 3.1.2
Am I doing something wrong?