Invalid Redmi Note 8T can't assign ringtone to varius contacts

[Kirlog]

Hello, I hope someone can help me. My mom bought a Redmi Note 8T (MIU Global 11.0.9). She want to add different ringtone do different contact (So for exapmle contact A has a ringtone and contact B has another). She manage to change the global ringtone, but can't assign other ringtone to contacts. First I though she can't find the option or something. But when i checked, even I can't add different ringtone. I find the option in contacts (contacts->select contact->3 dot in contact->ringtone), but when I select the ringtone, nothing happen. It still has the same global ringtone. Any idea what is the problem? I tried this with an mp3 file. Is the mp3 file the problem, or is it a bug? Are there any way to solve this?

 

[Igor Eisberg]

1. MIUI Global 11.0.9 has nothing to do with us, we're not Xiaomi Global.
2. Your description (contacts->select contact->3 dot in contact->ringtone) sounds nothing like MIUI Contacts app. On MIUI it's Contacts -> (tap a contact) -> Default ringtone (under "More"). So, I don't know which Contacts app you're using there...