Redhat – Samba authentication of user with wbinfo -a

i setup a RedHat server with samba/kerberos/winbind.

I can retrieve my user and groups with wbinfo -u and wbinfo -g.
BUT in the listings, the name appears like that :

wbinfo -u 

DOMAIN+username1
DOMAIN+username2
DOMAIN+username3
DOMAIN+username4

If i try to authenticate a user with wbinfo -a username1%password i've got this error :

plaintext password authentication failed
error code was NT_STATUS_NO_SUCH_USER (0xc0000064)
error messsage was: No such user
Could not authenticate user username1%password with plaintext password
challenge/response password authentication succeeded

If I put the domain into the username it works :

wbinfo -a DOMAINE+username1%password 

plaintext password authentication succeeded
challenge/response password authentication succeeded

But I need to have only the username and not DOMAIN+username, because I use an NTLM module in apache that needs to have only the username.

I have WinBind separator = + into smb.conf, so I don't understand why I must retrieve my users with the domain and the + symbol.