How to add a new host to WVD hostpool?

Christian_Montoya Hi Christian.  I have tried three different ways to add servers to a host pool.  It seems as though it is consstantly failing because of a conflict and I'm assuming because there is another computer there that it's trying to re-create with the same name?  Not sure.  But I've tried manually, Provision a host pool and the arm template and I cannot add more servers to the pool.  This iis essential as we are ready to increase this to a wider audience so we will need to get specifics down on how to expand these pools.  Thank you for your help.

{"code":"DeploymentFailed","message":"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.","details":[{"code":"Conflict","message":"{\r\n \"error\": {\r\n \"code\": \"PropertyChangeNotAllowed\",\r\n \"message\": \"Changing property 'imageReference' is not allowed.\",\r\n \"target\": \"imageReference\"\r\n }\r\n}"}]}

{"code":"DeploymentFailed","message":"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.","details":[{"code":"Conflict","message":"{\r\n \"status\": \"Failed\",\r\n \"error\": {\r\n \"code\": \"ResourceDeploymentFailure\",\r\n \"message\": \"The resource operation completed with terminal provisioning state 'Failed'.\",\r\n \"details\": [\r\n {\r\n \"code\": \"DeploymentFailed\",\r\n \"message\": \"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.\",\r\n \"details\": [\r\n {\r\n \"code\": \"Conflict\",\r\n \"message\": \"{\\r\\n \\\"error\\\": {\\r\\n \\\"code\\\": \\\"PropertyChangeNotAllowed\\\",\\r\\n \\\"message\\\": \\\"Changing property 'imageReference' is not allowed.\\\",\\r\\n \\\"target\\\": \\\"imageReference\\\"\\r\\n }\\r\\n}\"\r\n }\r\n ]\r\n }\r\n ]\r\n }\r\n}"}]}