Problems with the encodings of dictionaries ...

[zamok1980]

I created a RAR archive with a password in Russian - я (len of password - 1)
I tried (GPU GTX 1080 and GTX980):

hashcat -m 12500 -a 3 hash.txt ?b

and

hashcat -m 12500 -a 3 hash.txt ?b?b
but the password was not found((


When I created MD5 hash with same password - я, password was found successful..