Storyline 360 — Ai sound effect becoming inconsistent (missing/mistimed)

I have a click-to-reveal slide (base layer + 4 layers, each with its own tab/label). Each tab plays a short "click" sound via a Play Media trigger on click, and each layer plays its own narration audio that auto-closes the layer when it completes.

This was working reliably. I then added a 100%-transparent rectangle over the 4 tabs to block clicks until a gating condition is met later in the timeline. After adding it, the tab-click sound and the layer-end sound started behaving inconsistently, sometimes not playing at all, sometimes playing at the wrong moment.

The part I can't explain: I removed the blocker shape entirely to isolate the cause, and the audio issue is still happening even with the blocker gone.

• Has anyone seen audio triggers become unreliable after adding/removing an unrelated object on the same layer, even when the trigger conditions themselves haven't changed?
• Is there a known fix. re-saving, republishing, or rebuilding the audio triggers from scratch, for this kind of leftover inconsistency?

Storyline 360, base layer + 4 slide layers, each layer has "Pause timeline of base layer" enabled and its own Hide-on-media-complete trigger.