I'm not sure I understand what you have changed
If the jobs/job streams are defined to run on WorkstationA, updating WorkstationB to the IP address of WorkstationA will not work as the jobs/job streams will still be looking for the unavailable WorkstationA to execute the jobs
You would need to change the IP address for WorkstationA to the IP address of WorkstationB so that the jobs would continue to execute on WorkstationA albeit rerouted to the "underlying" WorkstationB system
Of course that all assumes that the scripts/exec/applications/etc. are also available from WorkstationB
What version of TWS/IWS are you using?