Sorry, If I got this wrong, but here's my suggestion:
- Make a common event in the database
- Make it parallel process
- Make it active via switch, called whatever you like (Let's name the switch "worldmap")
- Whenever you enter the world map, turn on that switch
- Whenever leaving the world map, turn the switch off
- It contains the following condition: If switch worldmap is on...
- ... change graphic -> Player -> None
- ... if it is not on...
- ... change graphic -> Player -> Sprite of your Charakter
I hope this will do it.