No tax Calculated on the basis of Province.

I hope you are doing great, I am facing an issue regarding the Province tax setup which is calculated only on FBR transactions but not in other provinces on PO. I have created two tax rates in FBR and they are implemented on transactions of FBR, but there are 7 more provinces which are, KPRA, SRB, PRA, BRA, GBRR, FATA, and PATA, in these provinces no tax is calculated on Purchase Order (PO). All provinces are added to the supplier and also tax registrations of all provinces are added to the supplier but no tax is calculated on PO except