GET request to /files/download fails with "The network connection was lost"

Hi,

The Joplin note taking app uses Dropbox's HTTP API  to upload and download files. Since a few days ago, some of our its requests are failing with "The network connection was lost".

The failing request downloads files from Dropbox using a GET request to content.dropboxapi.com/2/files/download:

fetch(
    "https://content.dropboxapi.com/2/files/download",
    {
        "headers": {
            "Dropbox-API-Arg": "{\"path\":\"/info.json\"}",
            "Authorization": "Bearer " + API_TOKEN,
            "Content-Type": "application/octet-stream"
        },
        "method":"GET"
    }
)

Sometimes, the above fetch does work. However, I can reproduce the failure consistently by sending the above request twice, but only in some environments:
 - Running code from the Safari development tools, inspecting a WebView embedded in Joplin.
 - Running code from the Chrome development tools, connected to React Native Hermes.

I can't reproduce this when using the same code in a NodeJS REPL or the Firefox JavaScript console.

The examples in the Dropbox documentation send POST rather than GET requests to files/download. Switching to a POST request does seem to fix the issue on Android. However, it still fails on iOS.

Another post on this forum suggests that fetch on iOS doesn't support sending POST requests with an empty body. Dropbox doesn't seem to allow a non-empty body for this request.

Is this forum the correct place to be asking for help with this issue? Is there a way to continue using a GET request to /files/download to download files?

Notes:
- The original version of this post was marked as spam, perhaps due to links to Joplin's source code and issue tracker. These links have been removed and can be provided on request.

- Joplin uses React Native 0.71. The issue still happens after upgrading to React Native 0.73.8.