It seems to be ok on Chrome and FF.
This is only a problem with MS Edge and IE
and only when using a 2-in-1 Device - with both touch and mouse support,
Win 8.x and Win 10 in my tests.
Windows 10 supports a Tablet Mode, which does not seem to make any difference.
FYI: My workaround:
I am not a javascript guy, but this was defeating my rollout, as the target users all have 2-in-1's
To make something workable i tweaked jquery-nt-menu.js
there is a timer in there that is set to 100 - it seems to control how long
the menu remains after navigating off with the mouse (or you finger in touch)
i bumped it up to 2000, and now the menu hangs around for 2 seconds, which is enough time to
make it workable, (it has a side effect of lingering a little longer for a mouse user, but for me a worth while trade off)
BRUCE: if that timer could be set from the menu template (or embed) , and you tweaked the shipping js,
that would make it a bit easier to deploy.