Process order not confirmed in RRP3

Hi Experts,

I'm facing an issue related to ATP confirmation in RRP3, need your help & advice.

This is happening with a Semi-finished product (and only to a single material). The quantities in R3 & APO are matching exactly. There is no backlog TQA in APO.

But when user is trying to create a Process orders, system books some qty, but the qty is not confirmed in APO. It shows 0 qty against 'confirmed qty' column in RRP3 view. Though the stock is still available in system, in ATP check, systems shows no stock available & do not assign any batch to the line item & do not release the process order.

Attached is the screenshot of RRP3 view:

We are searching why the confirmation is not done, although stock is available in system.

Could you please help in recognizing the reason for this?

Thanks in advance !!

Anurag Patki.