Basically, if you know you've won the hand and you press the Auto Drop Cards button and minimize the game window and you don't bring it back before the game won window comes up you cannot get back to the game. Alt-tab doesn't bring up, clicking on the icon in the taskbar does nothing. You have to end the task and re-launch the game.
Edit:
Game doesn't have this issue in Linux, at least not Linux Mint or ZorinOS, tested on both. If you minimize the game window while the cards are auto-dropping, when the last card auto-drops on the stack the window maximizes itself and the game won window is the active window.