B2B GOP Not considering the onhand in the shipping organization

Summary:

Hi Team,

I want to discuss with you on this case.
We defined a full setup for B2B to transfer quantity from organization A to organization B:
Local Souring rule for transfer from A organization to B.
ATP rule and assignment set.
The selling item has ATP stock in both organizations.
We create a Sale Order for B2B item, the GOP creates a transfer order from A to B.
B organization is the Shipping Organization, and A is the Sourcing one.
Why did the GOP create a Transfer Order from A to B and not, first, locate for shipping the ATP quantity that we have in A?