Solution
The reason of this behaviour is the default setting for the mouse in Windows 10. By default the setting
Scroll inactive windows when I hover over them in the Windows settings is turned on. If you switch this setting off, you can scroll again through large dropdown-menus. You can switch this setting off doing the following steps:
- Open the Windows Start Menu
- Open the Windows Settings by clicking on the gearwheel symbol in the Windows Start Menu
- In the Windows Settings panel click on Devices
- Click on Mouse & Touchpad on the left side of the window
- Switch Scroll inactive windows when I hover over them off: