project process configurator not creating event with correct amount

Summary:

On a contract, we have requirements to create deposit invoice (one time only) and a monthly rental invoice (to be created on 1st of every month) that includes fixed rental amount and calculated amortization amount (in negative). There are specific event types for rental amount and amortization events, respectively.

To meet the requirement, on the contract, there are two contract lines: 1) Deposit, and 2) Rental Invoice.
Contract Line 'Deposit' is assigned to 'Deposit Billing' billing plan. Event for Deposit will be created manually.

Contract line 'Rental Invoice' is associated with the same project but two tasks: one for Rental and one for Amortization.