This started to happen ~ a week ago. Steps:
  • Go to Sidebar -> Dashboards
  • Add widget 'Time Tracking' -> 'Time reporting'.
  • Set Grouping="User", 2ndLevel="None".
The totals hours are correct, but the times for tasks are all zero (0:00:00).
Additionally, there used to be a very handy action (on the right) to edit each task entry. It's not there anymore.