How can I configure Account Override to only request the username instead of a domain\username?

Hello,

I have a customer on v7.8.4 who is using the Account Override feature when a block page appears.  Whenever a user gets a block page, they can click the button for "Enter New Credentials" to apply a new policy.  When the user enters their username, they have to include the domain.

ex)

username: domain\user - this works

username: user - this does not work

In Triton Web Security > Settings > User Identification > Additional Authentication Options, I have included the domain in the "Default domain context" box but the credentials still require a username.  The customer is only using DC Agent to authenticate.

Besides adding the domain in that field, is there any other configurations I need to make to ensure that the Account Override will only require the username and not the domain\username?

Thank you,

Trinidad