Main Navigation dropdown hover flickering issue

[pxamike]

In desktop, especially with themes.configuration.menu.main.dropdownColumns = 1 enabled, when you hover from one top-level to across to the next (and it's subpages) it's possible to get stuck where on the first frame the first dropdown disappears and the second appears, on the second frame it's the reverse. And by this it continously flickers until the cursor is moved.