Cursor not contained within sim window

[stekusteku]

I fly in Reverb G2 and I have WMR desktop with me in the cockpit. When I need to interact with the cockpit with mouse (which I rarely do, as I have hardware panel) I have to bring the sim window to focus. If I want to operate the other apps on the virtual desktop (Pilot2ATC, Navigraph) I must release focus from the sim and go to desktop.
If the sim is in focus, the cursor is contained in the sim window. This is useful, as I don’t accidentally click anything on my virtual desktop. To go out of sim window, I just press the windows key on the keyboard (actually I have a button on the joke emulating windows key).
All this worked pretty well until recently. Randomly, the cursor is no longer contained in the sim window, so I can accidentally click anything on my virtual desktop (the worst case - clicking icon to close sim window!).

Any ideas why sometimes cursor is no longer contained within sim window? What is causing this? How to fix it when it happens?

[Mayhem6633]

I noticed some differences recently too. My cursor will get stuck in the WMR window and I can’t get to the WMR window;s close button or back into the game. To fix it sometimes pressing the windows-y key works. When that doesn’t work, I found I can switch to another desktop using the task view button next to the start menu, press win-y when I’m on the other desktop, then go back to the game. It’s not easy.