MDL-82570 changed help popover behaviour to address, I think, a fairly minor issue:  If the '?' icon was clicked, then the 'Esc' button pressed, then the '?' icon clicked again, the help popover would not reappear.  In the process, it has created, I think, a much bigger issue.  There's now no obvious way of getting rid of the help popovers using the mouse.  Neither clicking elsewhere, nor clicking on the icon again, will close the help popover.  It seems that the help popover can be closed by clicking on the icon again and then clicking elsewhere.  This is far from intuitive, though.

The issue seems to be in theme/boost/amc/src/loader.js enablePopovers() .  trigger was previously set to focus, which would close the help popover when the user clicked elsewhere.  Setting it to click would close the help popover when the user clicked on the icon a second time.  Instead it is set to both focus and click, and they seem to conflict.

So I think there are two approaches to fixing it:  Revert back to trigger by focus, or go ahead with trigger by click, and remove focus.  I don't know which is best.