Tax Substitution based on state is not working

I created a purchase order but while generating the invoice for the party between the same state
it does not set the substitute tax

steps i had done

  1. Created tax CGST , SGST , IGST and IGST 0% in one group
  2. Created Tax rule name IGST
  3. Selected Orignal tax IGST in tax rule
  4. Substitution tax IGST 0
  5. from subdivision and to Subdivision is same state of country
  6. Created product with SGST ,CGST and IGST
  7. assigned the party with tax rule
  8. created invoice with the party

but the invoice line does not show tax with the IGST 0 instead it shows IGST which has been assigned to product

can anyone pinpoint what i am doing wrong here ?

Is the right subdivision is set on the delivery address and on the warehouse address?

thanks a lot this sorted my issue