Purchase Order Requisition Charge account is not changing based on the Item Category

Hello All,

We are unable to change the charge account in purchase order requisition distribution form, Value is defaulting for all requisitions and it is non-updatable field.

In iProcurement charge account is changing based on the category, but in PO requisition it is not changing based on the category and it is defaulted for all items and non-updatable field.

Could you please let us know if any setup missing.

Thanks,