I posted the report of the original problem. Here is what I see with the test version:
Regular window
the map is a four rectangle checkerboard, I can see all the airports in green with their shadows but the top-left and bottom-right rectangles are white, the top-right and bottom-left rectangles display the sea and land correctly
Maximized window
after maximizing the bottom-left rectangle became white like the top-left and bottom-right one, the top-right rectangle displays just fine, or in other words, three quarters of the screen are white showing only airport names, the top-right quarter displays correctly

Thanks again for this awesome tool!