Yea, the map editor has some problems.
The workaround, for the map editor generating the same maps, is to generate the maps in the main program and then save them. You then reopen them from the map editor. The main SE4 program DOESN'T have this particular problem.
I did NOT know that the NO RUINS doesn't work. Again try using the main SE4 program for the initial map generation and then modify using the map editor.
Maybe SE5 will have a better map editor.