Remove last purchase rate in PO for ever

when we update ERPNEXT to v9 we removed LAST PURCHASE RATE in print of PO , but now we updated to V10 and again show LAST PURCHASE RATE in print of PO , how we can remove it for ever so next time we update again not come ?

Do you have a Custom Print Format or did you modify the Standard one? In case you have custom print format, don’t include the field on your custom print format

Thanks for your reply .
I customized PO and on “sb_last_purchase” click on “hide print” , but still show last purchase price in po , how we can hide it in PO ?