You already also tried "Ghastly Headset" app, to see which "speakers" are active atm? Even if not using headset it can be filled up with dust and can act strangely. It's always a good idea to remove dust... from headset jack when having audio probs (dozens of threrads about it here).
Ghastly Headset states:
On top there is an app "Audio Switch" which can route audio to several devices (Headset, BT, Backspeaker...) perhaps try this an attach e.g. headset to see if ringtone comes trough there to see that software is able to play those files.
"Current Media Mode is: ? "
"Currect Phone Mode is: ? "