Small 'gap' between menu bar & first dropped down item in Plone 5.1

[dgroos]

With standard Barceloneta theme in Plone 5.1 there is a small "gap" (see screenshot below) which, when moused over at regular speeds, 'drops' the dropdown menu (as if it weren't part of the responsive area of the menu). This is initially discussed on the Plone forum site.

[dgroos]

As a test, I just made a fresh install of Plone 5.1 (in a vm running Ubuntu 16.04 server) following the instructions on: https://docs.plone.org/manage/installing/installation.html.

Upon creating a site, I added webcouturier.dropdownmenu to the eggs, re-ran buildout, installed via site setup/addons. I made a folder at the root level and 1 item within that folder.

I hovered over the new menu item and got the same 'dead zone' gap as shown in the screen shot: