In a scenario involving more than one switchmgr command, agent cannot relink

You have been using the switchmgr command to switch to backup master domain manager, and then back to the master domain manager, but an agent might not have relinked to the original master domain manager.

Cause and solution:

The complex interaction of variables, environments, network conditions, and linking and relinking events can sometimes prevent an agent from relinking correctly.

No events or messages are lost, you can repeat the use of switchmgr, if necessary, and the performance of the network is not normally impacted because one agent is out of communication.

If only one agent is involved the easiest solution is to manually relink it.

However, to avoid having to identify and specifically relink the non-linked agent or agents, you can, in any case, issue the following command, which automatically relinks all agents without needing to specifically identify the unlinked ones:
JnextPlan -for 0000