When switching or changing scheduler roles the WA Agent may need to be updated.
Release : 11.3.x/12.x
Component : CA Workload Automation AE (AutoSys)
When the Primary scheduler is shutdown and Shadow is made primary the WA Agents may not respond to current (new) Primary server.
Run autoping from the new Scheduler. This will update agentparm.txt file of the with the new manager information.
E.g.
autoping -m ALL -S
See this documentation link for more details on autoping.