Check Q-INFO when create purchase order

Dear expert:

I have a issue about cerate purchase order,as below:

There is a Q-INFO without deletion flag ,
and then user can create a purchase order with same material same vendor if the document date is not later than Q-INFO's release date,
nevertheless,if the release date of Q-INFO expired(earlier than system date),

the purchase order still can be created or added new item which document date is not later than Q-INFO's release date.

My question is why the release date of Q-INFO check PO document date rather than system date?

Is any IMG settings can configure?
or which user exit can be?