Mouse movement leaves game and becomes standard cursor

I am having issues with both current live version and the new Community Test Environment release.

The CTE is incredibly worse though. Happens enough to not want to play

Desktop with wireless Logitech MX Master S2, Xbox 360 controller (in USB3) always connected
Laptop with wired USB2 mouse in a USB3 port, no other devices connected

Whats going on in both games is that im in combat, playing fine, more often than not issue occurs when I press mouse 2 to zoom in, the mouse looses focus of the game and becomes the standard OS cursor and I can not interact with the game. If I left click on the game screen, then Im back in the game playing until happens again, usually zooming in.

Doesnt always happen when zooming, can happen firing or just by itself.

The full version (desktop) does this too, not as frequently.

I play fullscreen (desktop 1080x1920 or with supersampling via nVidia driver) on the desktop, laptop set to 1600x900

Its like the mouse in game is leaving the the screen resolution and click outside of it, thus believing im clicking on another desktop screen or app (eg Alt Tab to another app) but the cursor stays over the game.

I have no external monitors set.

It is such a game killer for me, can not iterate with the game played..

Has been occuring for a while now.

Thank you

If the game loses focus it's because something else in your system forced focus on itself or you've opened a menu accidentally while in windowed/borderless mode (check your keybinds).