I got it!
I know how to alwasy reproduce it using Podcatcher.
Steps To Reproduce
- Enable Bluetooth
- Connect to a device
- Open Podcatcher
- Add a new podcast. For instance: Rhinoféroce - Couleur3
- Download a single podcast
- Play downloaded file with jolla-mediaplayer
- Minimize jolla-mediaplayer
- While you’re listening to good music, close
Podcatcher - Bluetooth connexion is over
- From Home, start music again → Sound is resumed and goes to speakers