Runtime BP Box Trigger and Events fire 3 times

Hello,
when i spawn a blueprint with a box collision, and then On Actor Overlap Event spawn a character, or a sound cue, the event processes three times (sometimes more). And this also happens when just executing a function for that blueprint’s Event Begin.

Event setup for box collision

Here the default audio component highlighted, and Event Begin Play loads the function once to spawn the boss character.

The SpawnBoss function

The corresponding spawned character blueprint does not contain any spawning of the same character, and the same setup is used elsewhere, without that issue.

The part which initially spawns the blueprint with the triple loaded character (via game mode)

Additional adding an audio component to the blueprint (which spawns at runtime), also loads three or more audio files from the associated music cue.

I tried to use DoOnce nodes, but didn’t help. Also tried to just activate the audio component on trigger, still plays three songs at once.

Any ideas why this is happening?

Demo video - YouTube

It is still unclear why a spawn actor node with a DoOnce node, initiated through a Begin On Overlap fires 3 times.

A fix is to add additional value checks, as seen in this screenshot

Bottom line, the Do Once node appears to have no effect on Game Mode blueprints?