Flux effect stays off when I alt-tab from a game

[The-1]

Hi
Whenever I go into a full screen application (game). When I exit or alt-tab to desktop, the screen is not dimmed / Flux applied any-more.
This occurs in Windows 10 but did not occur in Windows 8 and before.

As a workaround, I have to tell flux to disable and then re-enable to get it to work again.