Cross Site Replication seems not working in RHDG without any failure message

Issue

• The Cross Site Replication is configured on both sites according to the documentation but we don't see entries are replicated across the sites. There is neither an ERROR nor WARN message seen in the logfile.
• XSite replication is not working, the backup cache remain empty. After enable trace we found the following message within the primary site's logfile

TRACE [org.infinispan.remoting.transport.jgroups.JGroupsBackupResponse] Received response from site site2: CacheNotFoundResponse