Xiaomi's mobile phone can't change ringtones

Xiaomi can't change the bell. It may be that the ringtone file is relatively small, for example, less than half a m, which may have been filtered out by Xiaomi Music.

If this is the reason, the solution is to set it in Xiaomi Music. Xiaomi Music-My Music-Settings-More advanced settings-Filter by size (can be set to 0) or filter by time length (set to 0).

After the setting is completed, find the media file in the file manager or music file, click Play, then press the option to add it to the prompt tone of the ringtone, and then set it as the ringtone according to the normal procedure.