The AuthAnvil Windows Logon Agent (and Credential Provider) will only fall back to the local account database if no domain information is present.
If you need access to a local account on a domain-joined machine you can override the AuthAnvil Logon requirement by using the Override Password that you set up during the installation of the AuthAnvil Windows Logon Agent. More information is available in the AuthAnvil Windows Logon Agent Implementation Guide.
If you have any questions or need some help, we would be happy to assist. Open a case at kaseya.zendesk.com .