How to resize the window on Zorin
 

Every time I click on the settings, the window size is bigger than the desktop itself and it won't shrink even if I tried to drag the corners..

It is very annoying as there will be parts of the icons or options that are not seen unless I move the whole window.

You can try this: Hold down the ALT button and click and hold the left mouse button. You should be able to drag the window so that the edges are within the monitor borders so that you can click and hold the "handles" to resize the window.

zorin 16 window resizing
 

Alt right click drag does not work out of the box on this Zorin 16 I'm running either. Very annoying.
Alt F8 appears to be a default that can work for many but not all windows. A solution for all windows would be good, but I think Zorin OS has customised the wm a bit far.
Also when the windows are fully maximised I can't resize from any edge as I expect. Some way to bring back Alt right click drag would be marvellous.