ThinOS 9.3 RDP issues

I've got a Optiplex 3000 TC that we control in our environment by WMS. However, I can set up the connection but when I try to access it, all I get is "Server Denied Connection" with AVD at the top of the box. I'm not trying to use AVD but RDP as it's an on prem server I'm connecting too. I know the credentials, host, and domain are correct. Is there something I am missing? I have other TC's (this is the only 3000 TC we have, the rest are older TC's and AIO's) that connect just fine with no issues.