Windows 10 screen dimming when right-clicking Start (after fall update)

[Haggisman]

Argh, this is driving me mad, updated windows 10 this morning, and now whenever I right-click the Start Menu, the whole screen dims.

Also seems to do it when I right-click other built-in icons in the systray, e.g. volume control and network. Also sometimes randomly when I drag a desktop shortcut.

This is a desktop PC, I've checked power settings and there doesn't seem to be anything untoward in there, GTX 980Ti with latest drivers (updated this morning, but it was doing it before that as well).

Anyone else experienced this, and how did you fix it please?

 

[Haggisman]

Well, turns out this was actually the monitor dimming setting in DisplayFusion - looks like in the latest windows update, some context menus stop the monitor from being detected as active - disabled the setting and all is back to normal! (Now to get my start menu control panel shortcut back...)