While adding a new receipt for a PO with multiple lines, selecting a particular line leads to a blan

Hi, There's a PO with 3 lines on it. Trying to create a receipt for it on Purchasing > Add/Update Receipts page.

After selecting the PO and searching, see the 3 lines.

The 'PO Remaining Amount' checkbox is checked.

When I select either Line 1 or 3 for creating a receipt, the proper remaining amount on the PO is displayed as 'Receipt Price' on the next page.

However, when only Line 2 is selected, the 'Receipt Price' is set to blank.

Wondering why this is happening with Line 2 while Lines 1 & 3 are alright.