ora-12638 kerberos authentication multiple domains

We have oracle databases 12.1.0.2 on windows 2012.

we configured Kerberos authentication with local domain and it is working perfect.

Later we added xnet domain.

My new steps:

created the same account on xnet AD with same password. generated keytab.

merged both keytabs to one.

replaced old keytab with new.

modified krb5.conf added lines to Paragraphs: [realms],  [domain_realms] new lines with xnet entries.

modified  krb.realms added new xnet entries.

server created in local domain don't have any problems connect to database (client -> server);

server created in xnet domain give error ora-12638 in connection to database (client -> server);