Realize profits and losses on FX contracts
Upon settlement date for FX contracts you need to open the Add Contract transaction and re-save it again. The current FX rate will then be set as FX rate on the cash-flow in/out transaction in the Forward cashflow security in foreign currency. In that way the realized profit and loss is tracked on the Forward cash-flow security.
You can also use Tools - Realize PL on FX Forwards that sets the current FX rate on all the FX Contracts that have settlement on the current day. This is helpful if you have several FX Forwards that settle on a day.