Cisco Jabber (as of 12.9.1) will need to be reinstalled using an administrator Command Prompt by modifying installer properties. In the Administrator Command prompt, enter the command "msiexec.exe /i CiscoJabberSetup.msi UPN_DISCOVERY_ENABLED=false CLEAR=1" (without the quotes) from the directory where the CiscoJabberSetup.msi file is located.