The target core is using a different retention policy from the source core. You can set them the same or leave them with a different retention policy. Having the source save less recovery points and having the target core save longer periods of recovery points is ideal in most environments. Most DR (Disaster recovery servers) is setup to store more data for longer periods.
1) On the core select the agent and navigate to configuration tab
2) Navigate to retention policy and set the agent to use the core or set your own policy
3) Repeat the same steps on the target core to ensure you have set the same or different policies to meet your needs.