Activate Later Workflow Fails at Activate Page / Asset step

The environment has several publish agents on Author (10 or more) of which only one is enabled.  The others point to publish instances which are not running.

Basically, activating content works as expected, the content is published.  However, when the “activate later” option is selected, when the workflow reaches the activate date the activate content step in the workflow seems to fail with “Job contains agent which is not started” errors.  Sometimes more than one error shows.

18.01.2016 14:20:01.237 *ERROR* [pool-7-thread-16-com_day_cq_replication_job_flush(com/day/cq/replication/job/flush)] com.day.cq.replication.impl.AgentManagerImpl Job contains agent which is not started: flush. 18.01.2016 14:20:01.237 *ERROR* [pool-7-thread-11-com_day_cq_replication_job_publish11111(com/day/cq/replication/job/publish11111)] com.day.cq.replication.impl.AgentManagerImpl Job contains agent which is not started: publish11111.

There does not seem to be a clear difference between the activate page/asset step of the two workflows. 

The "publish11111" is Publish agent 6 and it is one of the ones that is disabled.

Any direction would be appreciated.