Sometimes, Event Destroyed of many Actors are being called in UE4Editor (not UE4Game) on map/level load even if you don’t use it on a map / level. That’s just how the PIE (Play In Editor) works to refresh the actors in editor.
Try using a a separate custom event (i.e., OnDeathEvent) to put your UI spawn logic. And then on your HealthCheck-like event, if its life goes to 0 (dead) then call the OnDeathEvent manually (instead of Event Destroyed).
In addition, if you put UE_LOG to print “Actor Destroyed” in your Actor’s C++ Destructor method, you’ll see many actors being created and destroyed by just playing and exiting from PIE (Play In Editor).