Time sheet line does get staged to Project Costing

I have the "Set the time to Project Costing after the time sheet line is approved" setup at BU level. I do not want the whole timesheet to be approved.

The approval is by "Operating Unit" by the "Expense Approver" for the time sheet.

I created a time sheet with two different operating unit. The approver of one of the Opr unit approved its time line. The status of the line change to "PAR" from "SUB". Now this line is not available on the expense processing page to be staged to Project Costing despite the BU setup.

However when the other line is approved by the other approver both lines get to "APR" status and is ready to be posted to Project costing.