Just to add to this post... I had the same problem with the score resetting using multiple worlds and found that the Score Label defaults to "All" Worlds I changed the setting to Current World and now it works as expected.
I added this to reset the score but it keeps crashing? Did you find a better solution or do you still have the rest running using the navigation button?
I use in The Opposite , score system for multiple worlds, I reset the score in every level (you pass the level when you achive one coin in that world) , if you play the game you will see Attempts and for every world it's set to see how many times you play that World . So if you achive one coin, redirect to Finish Level UI, but if you want to play it again , is not redirect you because is reset the score . So it's work properly