/458 and /460 cal Problem

hi experts

in feb month tax calculation of /458 and /460 is showing same

remaining wage types are calculating correct,

i am facing this problem for one employee ..

actual /458 is 17882

and /460 also showing 17882

but it has to be 17882/2=8941

please check the attached screen shot for the same

please tell me where is the problem

thanks & Regards,

SAJID