Georgij
I got an interesting reply from nothing support !
"1. If you choose chemical, a ringtone will be generated when contact A calls and paired with contact A. At this time, if you choose diode, the ringtone of contact A’s call will still remain unchanged (once the corresponding ringtone is paired, the ringtone of the contact will not change).
2. If you choose diode, when a new contact calls, a new ringtone will be generated that is consistent with the diode style
3. If your problem cannot be solved, you can go to Settings - Sound and Vibration - > Phone Ringtone, click the reset button in the upper right corner, and you can re-select diode or chemical. The ringtone will be regenerated when the contact calls"
Looks like I Can’t find the reset thing. 😅
And looks like my phone don’t react that way as the engine for the “only” one person that regularly call me have changed from diode to chemical ( first was not beautiful and then now it’s beautiful). So it’s strange.
But the idea behind this reply is coherent.