Media files downloaded to app's persistent data folder being deleted

Hi everyone.

In our app we are using media files which we download via that android download manager.
The files are being saved to the persistentDataPath for the app.
We have noticed that these files are disappearing randomly from the devices and this is proving to be a major issue.

I thought it might be something related to android's GC but:
A - I don't think it deletes files in the persistentDataPath
B - We tried to replicate the behavior by downloading the files and letting devices sit idle for 10 days but the files were still there

I would appreciate any help with finding out the cause for the file deletion, and advice regarding the best practices for media files downloading in general.
Our app downloads a large amount of files (our experiences have several pictures, videos and jsons that fully define it) and we use the android download manager to allow the device to keep downloading while the headset is not mounted.