Return PO and RG23 register

Hi

i got a problem while doing Return PO Process my RG23 Registers are not updating

my process is like

Create Po with returns tick activated

then GR(MIGO) with 161 movement type

then J1IS excise updation

but when i check the register RG23 part 1 and part 2 it is not updating it

can anybody help in this regards

Regards

Nk