I've had a problem since the map editor was implemented where whenever I would load a map with settings adjusted, a few of them (Mutators, and as of 2.0 themes, description, various texts, and few script functions) would reset to their defaults. While it isn't a huge problem for me as the maps and most of the scripts still remain intact, it really deters me from making more complicated scenarios due to the frustration of having to constantly reapply everything again when I want to make an adjustment.
So far, it seems loading a map "in progress" will simply reset the mutators to default only
Loading a "finished" map or importing a map will retain these mutators but reset the Primary Objective+Subheading+Objective Description, Victory Text, and reset the assigned themes of Undelords. It also will default a few scripts, such as triggering entity and spawning visual effects.
Customer support service by UserEcho