Retroactive Pricing isn't working as suspected

Hello,

I have a still opened blanket release,not yet invoiced, and I would like to update  price for items.

I had set up PO: Allow Retroactive Pricing of POs with value OPEN RELEASES, didn't succeed, price still remains the same after creating Retroactive Price Adjustment Account, updating release and submitting Retroactive price update concurrent request.

Afterwards tried to set up PO: Allow Retroactive Pricing of POs with value ALL RELEASES- in this case everything worked, price were updated.

So we come to the question, what could be reason that I cant update open releases only?

Also, is it really needed to have this Retroactive Price Adjustment Account, if we want to update Blanket Release that is still opened, not yet invoiced?( We don’t want to impact finance)