Upon exiting Rainbow Six Siege (from its in-game menu button), the game returns me to the Desktop, but "RainbowSix.exe" is not closing and the mouse cursor is stuck on top left corner. On my Windows machine, I have to press Ctrl+Alt+Del to select "Switch User" and log back in the same user to make it unstuck, but the "RainbowSix.exe" is still running. Alternatively, pressing Ctrl+Alt+Del and starting the task manager and manually closing the "RainbowSix.exe" makes the game let go of the cursor.
These issues are tied to one another - please investigate and resolve them.