Intercompany Warehouse Defaults in Sales Order Creation

We need your input on this matter. The company has started using the Intercompany process, which is functioning well. However, we are encountering an issue when the sales order is generated from the other company. Here's a sample scenario:

1. Create a Sales Order in ‘Company A’ for ‘Customer X’  - In this scenario Items are not available to ‘Company A’ so a PO will be created to order the items to Company B

2. Create the Purchase Order from the Sales Order in Company A. In the Vendor select Company B.

3. Purchase Order was generated from Company A to purchase the item to Company B. From here It’s still looks fine.

4. Then next step is to generate the Sales Order to Company B from Company A. (PO Screen > … > Intercompany > Generate Sales Order ). Sales Order is generated then switch companies to Company B.

Here is the issue: instead of defaulting to Warehouse 20 for Company B, the sales order is still defaulting to Warehouse 30 for Company A.

I've already checked the community, and it was mentioned that a customization will solve the issue by defaulting the Sales order to the correct branch upon generation. However, I need your input on where and how we should implement this specific customization. Thank you.