autostart.sh unexpected behavior

I have a remote playlist which I'd like to download, perform a simple search & replace, and save in a local path; the aforementioned steps should be executed on boot.

The first step is to download and edit the playlist. This can be accomplished with the following command:

curl 'remote-playlist-url' | sed 's/.ts/.m4v/g' > /storage/playlist.m3u

which produce the expected file.

The second step is to perform the first step on every boot. I have created a /storage/.config/autostart.sh file with the following content:

(
 curl 'remote-playlist-url' | sed 's/.ts/.m4v/g' > /storage/playlist.m3u;
) &

However, all I got is an empty file, and I don't know why nor how to debug the command.
Any hint would be appreciated.

Quote from vpeter

Network is not yet up. Somewhere in LibreELEC settings enable Wait for network.
Other option is to add before curl line sleep 5 or even little more time to get network up.

Honestly I thought the same, but AFAIK the content of autostart.sh is executed with this daemon, which should wait for the network because of this line:

After=network-online.target graphical.target

Anyway, I'll give it a try as soon as possible, thank you!

I have enabled Settings > LibreELEC > Network > Wait for network, and worked like a charm.
Thank you vpeter