I have music downloaded to my phone for long time. Yesterday I was listenning music for some time and Plex used ~500mb of cellular data.
The question is why, all the music is downloaded.
How to force plex to stop using data on downloaded content?
Are you using the plex mobile app or plexamp ? If plexamp, have a look under plexamp → settings > downloads as it gives a good amount of controls for cellular and when to prefer downloaded media.
If your using the mobile app then also check settings → downloads. There is an option there to use mobile data or not but to be honest I don’t use the mobile app for music so I cannot speak for how effective those settings are.
Plexamp uses mobile data as well, but it is less. I complained about long time ago and the answer I received is that it does not stream from your server, it uses the local files, but it will communicate with your server for “other reasons”. For example, if you are playing a file you can see in the server’s Dashboard that the file is been played. I myself consider all that BS, the whole point of downloading the media is to AVOID using data at all.
I was using mobile plex app. Settings->Downloads->Use mobile data was not set. So it did nothing.
It could be that I need to do a fresh installation (just to be sure that one of the latest updates did not corrupt some settings).
I am going to try plexamp (did not know about this app).
I use mobile plex application to listen to music only. I have checked android statistics and plex used 5-7GB of cellular data per month.