The Load correction status displayed on the 4263B LCD doesn't change to ON or OFF in response to the [:SENSe]: CORRection[:STATe] command.

Upgrade the firmware if it's older than Rev 1.05. Otherwise, take the following methods in order to control the correction mode:
A. To turn the Correction Mode ON, send the following commands:
i) "CORR:COLL:METH REFL3"
ii) "CORR:STAT ON"

B. To turn the Correction Mode OFF, send the following commands:
i) "CORR:COLL:METH REFL2"
ii) "CORR:STAT OFF"