I would like to set some not default ringtones to contacts.

If I set a custom ringtone as main ringtone, it works properly.
If I set a default ringtone to a contact (change main ringtone only in one contact), it works properly,

but when I set a custom ringtone to a contact, the phone rejected the calls from that contact after one ring.
I tried to copy the custom ringtone to /home/user/.ring-tones folder and the song appear on the ringtone list next to the defaults, but the result is the same.


Any suggestions?

Thanks.