Idk if this is because of Blueprintue, but this needs to expose the variable you are changing:
Just to clarify: In my case BPI Simple Interact is a blueprint interface I used to have it trigger with the character. You can do anything here as long as it triggers CompleteLevel event to move to next level. It could be reaching max point, arriving at X location, overlapping X actor, etc…
Aside from that think it’s the same from what I shared. Is it working as you expect or giving you any problems?