We had installed a version of UEM Endpoint Central 11.3.22 and we had installed the agent of that version on all the systems of the company, but we found that the DNS name of that server was problematic and we deleted the DNS records. After that, the Agents lost communication with the UEM server. After this, we deleted the UEM server and installed a server with the latest version. Currently, we cannot delete the previous Agent, we cannot update it, nor can we install a new version and we encountered a problem. Please advise what to do.