Unable to download media from the room's Files view, if the server has unauthenticated media access disabled

[Feliksas]

Steps to reproduce

1. Log in to a Synapse server that has enable_authenticated_media config option enabled (any Web browser)
2. Go to a room that has media posted
3. Click on the (i) button on the top right, go to Files view
4. Click the "Download" button for any file

Outcome

What did you expect?

The selected file is downloaded normally.

What happened instead?

A new tab is opened, taking the user to media/v3/download endpoint, server responds with a JSON like:

{
"errcode": "M_NOT_FOUND",
"error": "Not found"
}

it is basically the same issue, as described in element-hq/element-desktop#1911 (comment), occurs with any Web browser on any platform.

Operating system

Widows, Linux

Browser information

Chrome Version 131.0.6778.265, Firefox 134.0.1

URL for webapp

app.element.io

Application version

Element version: 1.11.90 Crypto version: Rust SDK 0.8.0 (21f7cc7), Vodozemac 0.8.1

Homeserver

Synapse 1.122.0

Will you send logs?

No