SRP2 Code

when we create New Item Code at the same time we enter the SRP2 (Subsection) fields in Category Codes in Item Master, but for one Item code, we have entered SRP2 (subsection) in category code,

When we create Sales order and enter the Item code and quantity then SRP2(subsection) should automatically populate in P4210 App. but only for this item, it is not appearing, somebody can help why?

thanks