Regression, kerberos + fallback ejb legacy security solution GSSAPI SASL mechanism not called

Given EJB secured with kerberos + fallback, using legacy security solution [1]
When I try to authenticate using correct Kerberos ticket and wrong username/password.
Then PLAIN SASL mechanism fails and GSSAPI is not performed.

Same scenario works correctly in

• 7.0
• 7.1 Elytron way

I have attached server.log for:

• no username password provided
• wrong username password provided

[1] https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.0/html-single/how_to_set_up_sso_with_kerberos/#configure-krb-remoting