We can’t reproduce the problem you describe. Can you please do the following:
Connect your device using mobile data (i.e., no wifi)
Download a podcast episode (you should see a toast informing you that the download has been queued)
Kill the app.
Start the app again.
When I follow these steps the app doesn’t download anything (to trigger the download I need to connect the wifi). If that’s not what you’re seeing can you please share application logs right after the undesired download has taken place?
There is actually a bug we are aware of where the mobile data preference was not being followed. This is fixed in the latest release 7.5.0 which is slowly making its way around. Since you have a PP, you can try sideloading it from the release announcement page if you don’t want to wait.