I have a strange problem that occurs only when unity runs stand alone and never when I'm in the editor. When I start my program, every buttons/sliders are available and are working fine, but if I increase the size of the window (either maximizing it or dragging it) every buttons/sliders that are now in the extended part of the window are not responding (the debug info told me that I'm on the UI root even when above one of them.). If I start with a larger window, no problem, I can shrink it, everything is fine and I can increase its size again without any problem. It really looks like the available area for the UI is defined at the start of the program and is never updated again.
Any help would be welcome

... Thanks in advance.