Hi friend.
Did the HWTACACS server reject usernames containing domain names?
If yes, you can configure the user name of the HWTACACS server to exclude the domain name and send the user name to the HWTACACS server.
Example:
To configure a user name not to contain the domain name, do as follows:
huawei(config-hwtacacs-test1)#undo hwtacacs-server user-name domain-included
Thanks.