Do you have the red breakpoint? If not just do this after the SpawnActor:
if(EnemyBlueprint == nullptr)
GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("NULL Enemy Blueprint!"));
if(enemy == nullptr)
GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("NULL Enemy Instance!"));