Exchange Rate Difference on UBR/UER How Project Accounting Handles

Hi

Our functional Currency is GBP and we have Project Setup in EUR (the customer is paying in EUR)

We have Revenue Booked in JUN-22 EUR 20,000 Exchange Rate 1 EUR= £0.91 (GBP)

DR: UBR GBP 18,200 (EUR: 20,000)

CR Revenue GBP 18,200 ( EUR: 20,000)

JUL-22: Invoice Raised for EUR 20,000 Exchange Rate 1 EUR= £0.88 (GBP)

DR: Trade Debtors GBP 17,600 (EUR: 20,000)

CR UBR GBP 17,600 ( EUR: 20,000)

In functional currency, we have UBR for GBP 600

The project is still continuing, for another few months. The business requirement is to Write of UBR as loss because for that EUR 20,000 customer has been billed and they have paid EUR 20,000.00

Can this be achieved in Project Accounting or do we have to do a manual journal in GL to record this as a loss by Debiting Forex Exchange Loss and Crediting UBR in GBP Functional currency?