For me I had to disable OpenJDK from sending banner notifications, ICE was generating them on start and when a connection dropped. I still get the windows notification chime, but I'm not randomly clicking myself out of the game now.
I run a dual monitor setup, with my primary 4k set at 1920x1080 full screen. (Desktop is at 4k on that monitor.) Randomly in game, if I click down near the lower right corner, either an action or selecting something to build, etc I get tossed to the desktop. I can tab back into the game, and for awhile it's safe to click in that region. If I'm paying attention I'll see that I don't get tooltips on icons in that area when it's acting up. If I don't click in the trouble area and instead alt-tab out and back I'm good to go for awhile longer in game. When I'm kicked out, or preemptively alt-tab out I'm not seeing any alerts/notifications/etc vying for my attention.
Anyone else run into this oddity?