Subject: Silent composition — nested track volume controls are undiscoverable, and one accepts changes it doesn't persist

Project: Cathy Hockey Multi Cam Video (project ID 7e92d24b-454a-4bb0-bd07-49b1caba3624)

Setup: Multicam workflow — a sequence built from one master audio file plus four camera clips (camera audio used for sync only), the sequence placed on a composition's script track. Desktop app on Mac, synced to cloud.

The problem: My composition played back completely silent, and it took the better part of a morning to find out why. The cause: the same audio track effectively has three separate volume controls at different levels — (1) the track inside the sequence in the media library, (2) the composition's own copy of that sequence sub-track, and (3) the parent script track in the composition. I set the volume to 100% at levels 1 and 3, in the places the UI naturally led me, and stayed silent — because level 2, the one that actually governs playback, was at 0% and is the hardest of the three to reach. Nothing in the UI indicates that a child track is silencing playback while the visible parent shows 100%.

Steps to reproduce:

Create a sequence from a master audio file + multiple camera clips; set track volumes inside the sequence.

Add the sequence to a composition.

In the composition, set the sequence sub-track volumes to 0 (e.g. while muting camera scratch audio).

Open the sequence from the media library and set its master audio track to 100% — playback of the composition remains silent.

Select the composition's script track — the properties panel shows Audio 100%, while the composition still plays silent.

A second, related bug (API/agent): The Descript project agent's track-modification tooling, when asked to set gain on a composition's sequence sub-track, reports success but the change does not persist — re-querying the document shows the gain reverted to 0. If sub-track gain isn't writable in that context, the operation should fail loudly instead of silently reverting.

Suggested fixes:

When a composition's effective output is silent because a child track is at 0, surface that on the parent — e.g. a muted-speaker badge on the script track and on the waveform, with a click-through to the offending layer.

Consolidate or clearly label the volume hierarchy — "this control affects the library sequence only, not compositions that already contain it."

Make the agent/API modify_track gain operation on sequence sub-tracks either work or return an explicit error, never a false success.