SO Order automattically closed with partial invoice.

Hey folks !

I create SO Invoice by adding lines from a sale order.

(I would like to invoice partially some lines of the sales order, So I created a new invoice, add the lines I wanted and change the quantity from 5 to only 1.)

But after that, the status SOLine statut is automatically change to “completed” even if there is unbilled qty .

Why ? I would to do multiple invoice from a same SO Order ?

Thanks for your help.