You means none of AD users are show up in TIC Web Console, right?
Does your TIC server join the target domain? If not, does the domain your TIC server joined is a trust domain to the target domain?
Can you provide more information for us to indentify the problem? Such as some screen shot or our support bundle.
About how to get our support bundle:
Login TIC Web Console.
Turn on debug mode: Sever --> Loggin tab --> Run in Debug mode check box.
Perform your operation, such as add domain credential, sync domain, and the add AD user…
Get the support bundle: click the ‘i’ sign on the top right corner --> Contact tab --> click ‘Generate a support bundle’ link.