When the mouse leaves the grid the headerbar gets focus and pressing Tab does not return the focus to the grid. Therefore in order to use the keyboard to operate the game, you have to place the mouse onto the grid.
It should not be necessary to operate the mouse in order to operate the game with the keyboard.
When the mouse leaves the grid the headerbar gets focus and pressing Tab does not return the focus to the grid. Therefore in order to use the keyboard to operate the game, you have to place the mouse onto the grid.
It should not be necessary to operate the mouse in order to operate the game with the keyboard.