A simple click anywhere outside of the dashboard and then saving and publishing should do the trick. I know it can be annoying but a click shouldn't hurt
Nope. And while clicking outside the viz does sometimes clear highlighting the one that drives me crazy is clicking a cell that then stays highlighted unless I click that same cell (or another one in the same chart, which just moves the problem to that cell). Just wanted you to know we all feel your pain.
I am experiencing the same problem.
The report i am working on has sensitive data And we would look to display it as a static image with no dynamic functionality added. Thus want to disable the option of highlighting a cell by clicking on it.
Here's a workaround: Create your dashboard, then as a floating element add a transparent PNG on top of that. The users won't be able to click on the underlying elements, because they'd be selecting the image on top.
In 8.1 empty worksheet might work as well.