No answers on TJC (https://together.jolla.com/question/...n-jolla-phone/), maybe here...

Hi
Can someone explain me what going on here... How Whatsapp detect audio files on the phone? (in setting for ringtone or notification).
For example in my case, Whatsapp see my audio files only from sd card (not all) and don't see any files from /home/nemo directory except from /home/nemo/android_storage/zedge/ringtone, but in this directory it see files ONLY downloaded from Zedge app. If I will put here other audio files, Whatsapp can't see them. WHY? Also if I will remove Zedge app, Whatsapp continue to see downloaded files in this folder.
Can it be that downloaded from Zedge app files stored in some txt file that whatsapp read? And maybe I can edit it if I will add any my custom files to this folder?
Any idea?
Thanks.