How to use the ProgressBar (in an Editor script)?

Seriously, it seems easy, but it isn't working for me.

It's easy enough to display it, and have a correct progress value, but it never goes away unless I use the cancelable version, and press the cancel button. No idea why it doesn't go away when it is done, is I have put EditorUtility.ClearProgressBar(); after calculations are done, but it doesn't seem to do anything.

my code is like this more or less:

 for (int x = minx; x < maxx; x++)
 {
     for (int y = miny; y < maxy; y++)
     {
         if (cancel)
         {
             EditorUtility.ClearProgressBar();
             return null;
         }
         
         //do stuff

         progress = (float)((x - minx) + (y - miny) * (maxx - minx)) / (float)(maxx - minx) * (maxy - miny);
         cancel = EditorUtility.DisplayCancelableProgressBar("Doing stuff", "", progress);
     }
 }
 EditorUtility.ClearProgressBar();
 return something;

So why does the progress bar only go away when I cancel, but not when it's done?