Logithèque: impossible to put the windows at full size

[InfoLibre]

I'm using Linux Mint Cinnamon 21.2 in VirtualBox, in a 800x600 screen. It's impossible to resize the windows at its full size, nothing happens when I click on the button:

[JosephMcc]

The most likely reason is that the window either can't be resized to less than 800 wide or 600 tall. The min system requirement for Mint is 1024x768 so this is a won't fix.