Performance Management is not collecting metrics on the device because it is shown as inaccessible in the discovery profile history.
CA Performance Management DX Performance Management
Disable (remove check box) for Create Pingable and Use ICMP and after removing the two options from the discovery profile (advanced tab) run the discovery again.
It the above does not help, go to the Data Collector server (if more than one then select the correct DC that manages the device) and do the following:
a) Ping the device
b) Collect a MIB dump from the device using sapwalk2 utility
See more in SNMP Querying Tools on site:
Does the above work? If yes then open a support case with Broadcom.