Even thought disable all mods, this bug still exists. And I found something interesting, if use a mod called Character Reload I can change the voice, like male vocie 7, it does changed, but if you try edit the character again, it still shows voice 1, but actually is voice 7. It still works after reload the game. But if is DCC, it will reset back to voice 1 after reload the game. NOTICE this bug still exists after disable all mods.
And I tried reinstall, back to 1.1.4, delete all documents in C:\Users\documents\Mount and Blade II Bannerlord but save data, all failed, righ now this bug seems only affect NPC lords and player in sandbox and campanign, soliders not include.
Yes, in latest version, steam. 1.1.5.21456