Hey,
Yeah it looks like because your containing the Logic in the Enemy the Do Once is running once Per Enemy instead of as a whole, assuming that is the one at the top of the screen.
Ideally, I would move the logic of creating that widget to the Player and probably create the widget on BeginPlay and have an empty state where it is Hidden and then use the Player to call a function that sets the looked at enemy as it looks towards and away from enemies which makes it visible and shows the Enemy and sets the needed info based on the passed in enemy.