when I double-click an existing task in the review section the task inspector / side bar panel slides in from the right side of the screen. Once I am done editing I click on the little triangle to the top right, just below the logout button. The task inspector then closes (slides to right) and opens again immediately (slides to left). If I then click on the triangle again, the task inspector closes. (Which is the expected behaviour, unless I am getting something wrong.)
This happens on both Firefox 51.0.1 and Chromium 55.0 on Ubuntu 16.10, in all views - standard, expanded, compact, grid.
Has anyone else noticed this behaviour? Zendone has been like this for a long time, I just have never taken the time to report it.