An info record is always valid if it exists, it is only the price condition that is valid for a certain period.
The info update indicator controls which info is written from the PO towards the info record, but not from the info record in direction to the PO.
There is nothing in standard to restrict the PO creation, except you use the source list and block this vendor as source.
There are many discussions in the community about how to stop price adoption from last PO, please search for it, it's a rule. , but this will only stop getting a price proposed, a user can still enter a price of his choice and create the PO.
If you really stop the creation of any PO if there is no valid info record condition then you have to make use of BAdI and/or User Exits.
Done through Enhancement,Thanks for your support
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