A proxy is likely being used on the Performance Center host. After receiving the 502 error, check the following file on the data collector host:
/opt/IMDataCollector/apache-karaf-2.4.3/etc/com.ca.im.dm.core.collector.cfg
If the below two entries reflect your changes, restart the dcmd process:
collector-manager-tenant-id=My New Tenant
collector-manager-ip-domain-id=My New IP Domain