That is NOT a bug. That is the way the Editor works.
Your description is not quite exactly correct however. Just turning the Editor on does not reset the score - at least I don't think so.
The Editor is intended for modifications to be done before
the game begins. Therefore, using it to make changes during the course of a game has all kinds of problems and can be done only within a narrow scope.
First, one always needs to be "paused" before turning the Editor on.
There are two ways (that I recall off-hand) to trigger the map regeneration
- Save the map
- Let the game run past a year's begining
The map regeneration
process resets all the Almanac data (except the date) to a "begining" status, resets the weather pattern, and resets ground elevation patterns.
Since it isn't a bug, it surely can't be fixed.