Intercompany Invoice in AP Invoice Header, how it will be auto-checked

Hello Everyone

Does anyone have any idea how the Intercompany Invoice checkbox gets automatically enabled in the AP Invoice Header?

We have a case where users are creating invoices between two entities. Initially, a default legal entity is populated from the supplier setup, and users are then changing the legal entity before entering the remaining details.

Earlier, after validating such invoices, the Intercompany Invoice checkbox used to get automatically enabled, and the Liability Account was updated based on the intercompany setup (different from the one derived from Manage Common Options for Payables and Procurement).

However, this is no longer happening. Now, when we follow the same steps and validate the invoice, it goes on