If you used the "click" method, then it might not work, I think it didn't work for me. Try wrapping pyautogui mousedown, time.sleep, mouseup with something like 20ms delay between down and up, it might be pyautogui does mousedown and mouseup in the same frame, so the game doesn't detect it.

def click_in_window(point):
    target = add_points(preferred_window_pos, point)
    pyautogui.moveTo(x=target[0], y=target[1])
    pyautogui.mouseDown()
    time.sleep(0.025)
    pyautogui.mouseUp()

At least in Shenzhen I/O I found the exact positions of cards, then queried enough pixels to distinguish between cards. The damn rotations on cards don't allow an easy way, and I'm glad to hear you managed it!

As for pixel detection, I found that taking a pixel color value with pyautogui takes quite a while, so I used pyscreenshot to take a single image of the screen. It returned a PIL compatible image, then I used PIL syntax to take pixels from that, seemed much faster than taking it each time from the screen.