Quick answer: Construct 3 Trigger Once While True event firing repeatedly when condition flickers? The 'once' resets when condition becomes false; rapid toggles re-arm it - debounce the condition.
Door triggers an alarm. Alarm fires every frame because the trigger condition oscillates.
Add a debounce
Track 'last triggered time'; ignore re-trigger within 0.5s. Eliminates oscillation.
Or use a state machine
Explicit Armed/Triggered/Cooldown states. Each state has its own conditions; no implicit re-arming.
Audit the condition
If the condition rapidly oscillates, the upstream logic has a bug. Fix the upstream rather than dampening the symptom.
“Trigger Once While True is convenient. Convenient assumptions about oscillation cause bugs.”
For mission-critical triggers, explicit state machines beat sugar. The boilerplate pays for itself.