Captions not refreshing from copied AI audio

Hi all,

I’ve run into an issue with AI audio and closed captions in Storyline 3 and wanted to share this with you, and even check if this is expected behaviour or a bug.

Yesterday, I saved an existing Storyline project as a new file for a new piece of work. The original project already had slides and AI‑generated audio. I replaced the images on those slides and then opened each AI audio clip via AI Text to Speech (editing mode) to replace/overtype new text with my new content, left the “Generate closed captions” option ticked (it’s ticked by default), generated the new AI audio, and then updated it on the timeline.

However, when I previewed the full project, none of the new captions had been generated. The audio had updated correctly, but the captions were still from the original project.

The only workaround I’ve found is, which is a manual task and I have so many slides:

Right‑click the AI audio on the timeline → Closed Captions → Generate

This works, but it’s time‑consuming and unexpected, because I thought that editing the AI audio text and leaving “Generate closed captions” ticked should automatically create the new captions.

Is anyone else experiencing this? Or is this a known issue?

Thanks in advance.