You wouldn’t loop directly back to the reset after the play sound. The whole sequence happens so fast that it defeats the purpose of the “do once.” Generally you would have another event reset the do once, or at the very least have a small delay before resetting.
That doesn’t seem like the issue though, since in the video it only spawns the sound once, yet you hear the sound over and over. I can’t read much of your blueprints because it’s not in english, but I suspect your issue is in some other area. Do all the sounds in that sound cue have a gore element to them? I’m hearing some sword hits with no gore sound.