Mouse not captured by window in multi-monitor setup

I have a dual-monitor setup, with Insurgency playing on the left screen. When moving my mouse around in game, it seamlessly moves into the second monitor to the right. Then if I click somewhere on that second monitor Insurgency loses focus and I can't shoot or do anything until I click back into the window. This of course makes the game unplayable as long as I have the second monitor on as I'm constantly clicking outside the game while aiming. I have tried switching the video settings to windowed, borderless windowed, and fullscreen with no change in behavior.

Windows 10

I got 3x monitors and I have not had that issue you describe, when in menu I can run mouse over to the other desktops and browse, ingame it's locked and working correctly.

Also the buddy I play with got a 3x monitor setup and I don't recollect him having the issue.

I hope it gets solved for you in one way or another.