Above is a sample of custTrans with partial settlement.
We created a new customer for a clean simulation, Invoice and Payment both have the same Financial Dimension.
On the first settlement, there is no seperate settlement record on custTrans, but after we reverse the settlement and re-settle, it create the settlement transaction.
Other scenario we faced, involved import customer opening balance with journal, every payment transaction have settlement line until the accumulate balance is zerorized.