Solution 1:
- press the ALT and SPACE keys while you over the Lychee Slicer icon, a little menu should appear
Solution 2:
use one of thoses options when you right click on the windows taskbar (not on the icon)
- cascade windows
- show windows stacked
show windows side by side
Solution 3:
  1. Click on the Lychee Slicer icon in the taskbar
  2. Press the keys WINDOWS + SHIFT
  3. and while you hold the WINDOWS + SHIFT keys, use the arrow of your keyboard to move the windows (you will probably need to press few times in left or right to try to bring it back to your main screen, this manipulation moves windows from a screen to another screen