Cycling the robot will force it to pull in the new IP or you can do the override if they're not picking the correct IP at startup.
Here's an example of a .BAT file to update the override using a provided list of server IP's:
@ECHO OFF
SET PASSWORD=blahblahblah
FOR /F "tokens=*" %%A in (RobotList.txt) do (
pu.exe -u administrator -p %PASSWORD% -H %%A probe_config_set controller controller robotip %%A NULL NULL
pu.exe -u administrator -p %PASSWORD% -H %%A -R
)
PAUSE