Thanks for your answer.
My phone is in Spanish, so maybe i'm not translating correctly what it's written in the menus:
Audio engine>output>reset default
Audio engine>output>high resolution output>reset default
Audio engine>output>high resolution output>gear icon on headphones/aux>reset default
then, turn on hi res output switch for the wired headphones. Problem persist: selected 192 kHz, using 48 kHz.
As I said, I uninstalled the app and reinstalled again, different versions, not importing the config file, and the problem was not solved.
I always use wired headphones (mi hybrid). Only once I used bluetooth in a car. Never USB dac.
AFAIK, it is using DVC, as the option "without DVC" is disabled by default and I keep it disabled. Anyway, I have restored defaults...
I tried changing the phone region from Spain to Taiwan (JIC it is related with EU volume limit) but not solved. Anyway, I knew it wasn't the reason, because I tested that when it still worked properly. For sure, I have rebooted the phone many times
Do you need more info? Just tell me and I will try, but I'm not root.
Edit: I have exported current setting, delete all data, open the app again, and the problem persists. But now I have lost the backup (as I should have expected...🤦♂️)