Menu drop-downs appear on the wrong screen.

Steps to reproduce:

• open Inkscape
• move the window to a second monitor above the primary
• click on a menu

What happened?

The dropdown menu appears at the top edge of the primary screen.

What should have happened?

The dropdown menu should appear below the menu that was clicked, on the secondary screen.

Inkscape Version and Operating System:

• Inkscape Version: 1.0alpha (94f43655, 2019-02-05)
• Operating System: Windows 10
• Operating System version: 19h1_release 18329 (insiders)

This screenshot shows the result of clicking on the 'Filters' menu in the above situation: