The error seen in ppm logs comes from the rsp probe when triggering the discover host:
Jul 06 10:29:57:920 [attach_socket, ppm] (Adapter) (3) invalid argument, Received status (3) on response (for sendRcv) for cmd = 'discover_host'
rsp.log:
Jul 18 06:35:16:928 [6696] rsp: GetConnection: Get DB connection
Jul 18 06:35:16:928 [6696] rsp: GetConnection: Connection object found in Pool
Jul 18 06:35:16:928 [6696] rsp: thrDiscoverHostWeb: Using global timeout value, 30 seconds
Jul 18 06:35:16:928 [6696] rsp: thrDiscoverHostWeb: Called with hostname=xxx
Jul 18 06:35:16:928 [6696] rsp: thrDiscoverHostWeb: Hostname resolved to xxx
Jul 18 06:35:16:928 [6696] rsp: thrDiscoverHostWeb: Detecting the IP address for the specified host
Jul 18 06:35:16:928 [6696] rsp: sockClose:00000249EFE7D090:##.##.#.#/####
Jul 18 06:35:16:928 [6696] rsp: thrDiscoverHostWeb: Discovering OS
Jul 18 06:35:16:928 [6696] rsp: ConnectWMIServer: Establishing TCP Connection to WMI Host xxxxxx
Jul 18 06:35:16:928 [6696] rsp: ConnectWMIServer: Sleep 195 milliseconds for WMI connection to xxxxx
Jul 18 06:35:17:147 [6696] rsp: sockClose:00000249EFE7D090:##.##.#.#/####
Jul 18 06:35:17:147 [6696] rsp: ConnectWMIServer: TCP Connection to WMI Host xxxxx failed
Jul 18 06:35:17:147 [6696] rsp: Windows do_connect: connection failure
Jul 18 06:35:17:147 [6696] rsp: thrDiscoverHostWeb: Connection attempt with xxxxx failed.
Jul 18 06:35:17:147 [6696] rsp: (SNAP Path)Time taken in discovering xxxxxx=1
Jul 18 06:35:17:147 [6696] rsp: SREPLY: status = 3(invalid argument) ->##.##.#.#/####
Jul 18 06:35:17:147 [6696] rsp: do_disconnect: starting disconnect
Jul 18 06:35:17:147 [6696] rsp: do_disconnect: no connection
Jul 18 06:35:17:147 [6696] rsp: CleanDatabaseObject: Closing the local db connection
Jul 18 06:35:17:147 [6696] rsp: FreeConnection: Connection released
Release : 20.4
Component : UIM - RSP
Please set at rsp probe
WMI connection timeout = 20 sec
Command Timeout = 50 sec
wmi_retries = 3